Boston Red Sox Offseason Target: P Zac Gallen

[Nick John]

The Red Sox were able to make the playoffs in 2025 thanks in part to their deep carousel of starting pitchers. Despite losing quite a few to the injured list, the team was able to replace them with their depth right up to the end of the season. However, with the team likely needing to replace a few spots in the rotation for 2026, they may need to explore the free agent market to find a replacement.

Last offseason, the Red Sox brought in three pitchers to join their rotation in the form of Garrett Crochet, Walker Buehler, and Patrick Sandoval. Of the three, only Sandoval failed to get into a game in 2025. Buehler did not make it through the season with the Red Sox, however, being released at the end of August due to poor performance.

While the rotation will have Crochet and Brayan Bello in it to begin 2026, the three remaining spots are up for grabs, as it’s likely Lucas Giolito will leave in free agency, and it isn’t certain that young pitchers Payton Tolle or Connelly Early will be able to win a job out of spring training. Options like Kutter Crawford and Sandoval also remain, but there’s no guarantee when they could get into games that matter after their respective injuries.

Because of that, the Red Sox may have to turn their attention to the free-agent market to bring in a veteran to replace the innings provided by Giolito. In the same way that they signed Giolito to a two-year deal after he struggled in 2023, the Red Sox could replicate that with another former All-Star and Cy Young contender in Zac Gallen.

Gallen, 30, will be two years older than Giolito when the Red Sox originally signed the former White Sox pitcher. In his age-29 season, there is no debate that Gallen struggled mightily, as he went 13-15 with a 4.83 ERA in 33 starts. In that span, he threw 192 innings and allowed 31 home runs while striking out 175 batters. In Giolito’s age-28 season before coming to Boston, he went 8-15 with a 4.88 ERA in 33 starts. The right-hander tossed 184 1/3 innings while allowing 41 home runs. He did, however, strike out 204 batters.

The similarities are there, and it could be an interesting discussion for the Red Sox to attempt to sign Gallen to a deal similar to Giolito’s. A two-year deal with a third-year mutual option might entice the right-hander after a rough 2025 may have lowered his value.

With that, let’s look at how Gallen could be a fit for the Red Sox rotation in 2026.

The Good:

Right away, Gallen gives you innings. Since 2022, Gallen has tossed at least 184 innings every year except for his 2024 season where he missed starts. And in 2023, he crossed the 200-inning threshold. A former All-Star and Cy Young contender, Gallen could be the perfect number three or four in the rotation to go out and provide six to seven innings each night while affording the team a chance to win.

When it comes to his pitch arsenal, Gallen meets a quality that @Brandon Glick mentioned in his article on the Freddy Peralta and the Red Sox. In it, he mentions about Andrew Bailey and Craig Breslow valuing pitch-tunneling (the ability to hide your pitch while having late movement to force a batter to change their eye level late during the pitch). This can also be created through shape and movement of pitches.

Gallen himself has unique movement on all his pitches except for when it comes to his slider and cutter, two pitchers he uses sparingly. His three main pitches are his fastball, curveball and changeup, a similar smattering of offerings to Giolito, who relied on a fastball, slider and changeup. In Gallen’s case, his main three pitches force hitters to change eye level often in an at-bat, and it wouldn’t be a bad idea for the Red Sox to try and alter the shape of Gallen’s slider or cutter to take on a more sweeper shape to help create more horizontal movement.

While 2025 was rough for Gallen, the right-hander previously was one of the best starters in the National League from 2022-2024, when he was a two-time top-5 Cy Young Award finisher and received MVP votes while leading the Arizona Diamondbacks to the World Series in 2023.

Along with that, Gallen’s ERA and FIP were both higher than expected in 2025, showing that he may have gotten unlucky at times. His expected ERA was 4.39, nearly half a run lower than his 4.83 ERA, and his expected FIP was 4.12, a whole 0.38 lower than his 4.50 FIP. Should Gallen increase his ground-ball rate form 44.4% and lower the amount of home runs he allows, he could see a closer return to his previous performance.

The Bad:

Simply put, Gallen did not look like the pitcher he had been in prior years. He gave up a career high in home runs, earned runs and walks while having the lowest ERA+ of his career at 89, suggesting that he was a below-average pitcher in 2025. The 31 home runs may have been the worst aspect, as he had a 14.6% home run to fly ball rate (HR/FB) while allowing almost 38% of his batted balls to be fly balls. To get back to his old self, he would need to limit the long ball, especially in a stadium like Fenway Park. Fortunately, Giolito is a template for how the Sox managed to turn a pitcher who allowed a ton of home runs into a more modest amount, going from 41 home runs in 2023 to just 17 in 2025.

In a league where velocity is also important, Gallen’s fastball averaged just 93.5 mph with batters slugging .413 off of it. The bigger issue is how his sinker and cutter were hit even harder, as batters hit .294 and .370 and slugged .529 and .761 against the two offerings, respectively. If the Red Sox were to bring him in to join the rotation, it would be important to rework those pitches in his arsenal or to even drop them completely.

Beyond all that, Gallen just wasn’t very good at any one thing last season. His strikeout rate of 21.5% was the lowest of his career and led to a career-low strikeout-to-walk ratio of 13.4%. Likewise, he had the worst ERA- of his career at 114, a huge increase from 2024’s being just 88 (the lower the number the better when it comes to ERA-). Of all qualified pitchers on FanGraphs' rankings, Gallen ranked 45th in ERA-. Of all pitchers with at least 100 innings pitched, he would rank 98th. Again, it doesn’t tell the entire story, as Giolito also had an ERA- of 114 before rebounding with Boston in 2025 to the tune of an ERA- of 80. Gallen is someone who could benefit from the same coaching that Giolito went through in 2025.

The Verdict:

Gallen checks off a lot of boxes that the Red Sox would like to have in a veteran to help the backend of the rotation. He gives you innings, has been mostly healthy throughout his entire career and has postseason experience to help guide the young pitchers. It would be crazy to not check in with Gallen’s camp during the offseason, especially with the uncertainty surrounding Giolito’s return to Boston.

The Red Sox do need a true number two to pair with Crochet and while Gallen may no longer fit that profile, signing him would allow the team to then turn its focus to the trade market. While the likes of Joe Ryan, Hunter Greene, and Freddy Peralta are more exciting names, Gallen is also someone who could provide a huge boost if he rebounds from a tough 2025 season.

Currently, MLB Trade Rumors has Gallen's value pegged at four years and $80 million, with most experts expecting him to stay on the West Coast. I don’t think it makes much sense to sign Gallen to more than two (guaranteed) seasons given how his 2025 season looked. As mentioned previously, if you can get him on a contract similar to Giolito, it could turn into a steal. Given that he rejected a qualifying offer from the Diamondbacks, his market could drop to a level the Red Sox are comfortable with, especially if they are willing to offer him a short-term deal with a high AAV that would allow him to return to free agency if he bounces back from his recent struggles.

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[Larry Cook]

Most writers say that bres-slow and Bailey value strike out % pitchers and the two names mentioned most frequently, Ryan and Greene have the same type strike out % as giolita had when we signed him. 
 

 

[moonslav59]

I would not spend large or long on Gallen.

[Larry Cook]

11 hours ago, moonslav59 said:

I would not spend large or long on Gallen.

Agreed! I think Atlanta has interest in him 

[mvp 78]

Gallen has a QO attached and less than 4 fWAR the past two seasons combined. Pass. 

[JoeBrady]

A two-year deal with a third-year mutual option might entice the right-hander after a rough 2025 may have lowered his value.

I'd have thought the author would've checked out MLB Rumors to find out that a 2-year deal was very unlikely.

And, as mvp 78 pointed out, Gallen has a QO.  I'd have thought that would be something of interest for the writer to include.

Basically, a hard 'no'.  There is no assurance that Gallen will be better than either Sandoval or Early.  Spending $20M on Gallen is a non-starter given our other concerns.

[drewski6]

PASS - 4seam, curve, change is boring mix, the only thing you can really tunnel there is the change, assuming its a regular change and not a circle change.  Thats not really a tunneling mix. Plus QO and 20m? Id rather just retain Gio between the two.

[drewski6]

The pitches that tunnel the best are the slider off the 4 seam (or cutter) or the cutter off the 4 seam or the circle change off the sinker (same shape) or the sinker off the 4 seam (late break) or even the splitter off the 4 seam (late break)

YOu cannot tunnel the curve or the sweeper.  Its gotta look like a fastball out of the hand , and curveballs and sweepers do not.

[notin]

We all agree this is an easy pass. 
 

Which brings up the obvious question - so what uniform number does he get?

[mvp 78]

6 minutes ago, drewski6 said:

The pitches that tunnel the best are the slider off the 4 seam (or cutter) or the cutter off the 4 seam or the circle change off the sinker (same shape) or the sinker off the 4 seam (late break) or even the splitter off the 4 seam (late break)

YOu cannot tunnel the curve or the sweeper.  Its gotta look like a fastball out of the hand , and curveballs and sweepers do not.

How did Kershaw even last this long in the league with just that curveball? 🤔

[mvp 78]

Just now, notin said:

We all agree this is an easy pass. 
 

Which brings up the obvious question - so what uniform number does he get?

67

[notin]

4 minutes ago, mvp 78 said:

67

The correct answer is 23.  With Arizona.

I put Gallen as the second most likely to accept his qualifying offer, tied with Woodruff, behind only Michael King

(I got the 6-7 joke, but not sure how many others did.)

[drewski6]

1 minute ago, mvp 78 said:

How did Kershaw even last this long in the league with just that curveball? 🤔

You can be effective without a well tunneled slider, obvs. Just weird that the article is talking about how Gallen checks the tunnel box, which is something that the sox look for, when Gallen doesnt have a slider.

Most of the time, when people are talking about tunnelling it means that the slider looks like a fastball out of the hand for a long time because it stays in fastball shape for longer (late-sharp break on slider).  For a well tunneled slider, you have to look for the dot on teh ball, and not the shape, because the slider shape doesnt reveal until after you have to make your swing decision. Its not accurate to talk about tunnelling a curveball or a sweeper becuase thats not what they are even trying to do (look like a fastball until last second).

[drewski6]

1 minute ago, notin said:

The correct answer is 23.  With Arizona.

I put Gallen as the second most likely to accept his qualifying offer, tied with Woodruff, behind only Michael King

(I got the 6-7 joke, but not sure how many others did.)

gleybar torres?

[drewski6]

tunnelling means stays in the fastball tunnell longer.  Which means the slider has "carry". Its not dropping, its not breaking, its not sweeping. It looks like a fastball all the way , and then you have to make your decision, and then poof , it runs away from you (righty/righty or lefty/lefty), strike 3.

[notin]

7 minutes ago, drewski6 said:

gleybar torres?

I could see that.  But I think King, Gallen and Woodruff are more likely since they’re all coming from down or injury-plagued years.  Torres had a mild bounce back season.

This does raise the question - why wasn’t Giolito offered a QO?

[JoeBrady]

1 hour ago, notin said:

I could see that.  But I think King, Gallen and Woodruff are more likely since they’re all coming from down or injury-plagued years.  Torres had a mild bounce back season.

This does raise the question - why wasn’t Giolito offered a QO?

Because he might've accepted it?  This wasn't just a last-minute injury.  Maybe it wasn't as urgent earlier, but his K/W in his last 9 starts was 40/29, or 7.30/5.29 per 9.  That's really alarming, injury or not.

[JoeBrady]

1 hour ago, drewski6 said:

You can be effective without a well tunneled slider, obvs. Just weird that the article is talking about how Gallen checks the tunnel box, which is something that the sox look for, when Gallen doesnt have a slider.

Most of the time, when people are talking about tunnelling it means that the slider looks like a fastball out of the hand for a long time because it stays in fastball shape for longer (late-sharp break on slider).  For a well tunneled slider, you have to look for the dot on teh ball, and not the shape, because the slider shape doesnt reveal until after you have to make your swing decision. Its not accurate to talk about tunnelling a curveball or a sweeper becuase thats not what they are even trying to do (look like a fastball until last second).

Nice descriptions on all your posts.  The only thing I know about pitching is that it's hard to hit.

[Larry Cook]

1 hour ago, notin said:

I could see that.  But I think King, Gallen and Woodruff are more likely since they’re all coming from down or injury-plagued years.  Torres had a mild bounce back season.

This does raise the question - why wasn’t Giolito offered a QO?

Maybe the Sox want to try to sign giolita to a multi year deal at a lower rate? 
 

or 

maybe the Sox saw something in his medical and just want to cut bait 

[moonslav59]

I think Gio has some sort of injury. I'd pass.

I really don't like this year's FA pitching class all that much. Most seem to be coming off an injury or a down season (or both.) Others are past prime.

Trading for a pitcher is no guarantee, but we seem to have better luck that route. (Maybe it's not luck, since trading for proven but younger pitchers helps up the odds on success.)

[5GoldGlovesOF,75]

Didn't Gio turn down a $19 mil option? If the Qualifying Offer is about $22 mil, that's not much more and doesn't make sense for him to accept, since he's most likely looking for at least two or three times that in a multi-year deal.

 

[moonslav59]

1 hour ago, 5GoldGlovesOF,75 said:

Didn't Gio turn down a $19 mil option? If the Qualifying Offer is about $22 mil, that's not much more and doesn't make sense for him to accept, since he's most likely looking for at least two or three times that in a multi-year deal.

 

Yup, but what he's looking for is half the way there. The other half is what the highest team offer is.

[JoeBrady]

2 hours ago, 5GoldGlovesOF,75 said:

Didn't Gio turn down a $19 mil option? If the Qualifying Offer is about $22 mil, that's not much more and doesn't make sense for him to accept, since he's most likely looking for at least two or three times that in a multi-year deal.

 

It was a mutual option.  He's better off declining the RS than waiting for the RS to decline him.

[Randy Red Sox]

2 hours ago, moonslav59 said:

I think Gio has some sort of injury. I'd pass.

I really don't like this year's FA pitching class all that much. Most seem to be coming off an injury or a down season (or both.) Others are past prime.

Trading for a pitcher is no guarantee, but we seem to have better luck that route. (Maybe it's not luck, since trading for proven but younger pitchers helps up the odds on success.)

yet the Sox have tended to go the rehabbing SP route more often the past few years.

[Randy Red Sox]

1 minute ago, JoeBrady said:

It was a mutual option.  He's better off declining the RS than waiting for the RS to decline him.

If his price drops significantly the Sox may be back in. They like signing rehabbing pitchers on short term deals.

[moonslav59]

2 minutes ago, Randy Red Sox said:

yet the Sox have tended to go the rehabbing SP route more often the past few years.

We have Sandoval, so maybe we've set a new limit.

(And Houck, Crawford, Dobbins...)

[Larry Cook]

52 minutes ago, moonslav59 said:

We have Sandoval, so maybe we've set a new limit.

(And Houck, Crawford, Dobbins...)

Dobbins says he will be 100 percent ready to compete for spring training. 
not sure the Red Sox trainers agree, but I like his positive attitude 

[moonslav59]

33 minutes ago, Larry Cook said:

Dobbins says he will be 100 percent ready to compete for spring training. 
not sure the Red Sox trainers agree, but I like his positive attitude 

He's still just one of four.