What Are the Red Sox Gonna Do With Marcelo Mayer, Now?

Marcelo Mayer has made his presence felt at spring training. As of this morning, he’s played in seven games, posting a .294/.368/.588 slash line. He's running a 26.3% strikeout rate, 10.5% walk rate and 145 wRC+ with one triple, one home run, and five RBIs. Defensively, he’s split time evenly between shortstop and third base. Here's his game log:

• 2/22 vs Rays: DH
• 2/23 vs Blue Jays: SS
• 2/25 vs Braves: 3B
• 2/27 vs Tigers: 3B
• 2/28 vs Phillies: SS
• 3/2 vs Mets: SS
• 3/3 vs Orioles: 3B

Before the meteoric rise of Kristian Campbell and Roman Anthony, Mayer was Boston's number one prospect. Due to a left shoulder strain in 2023, he was restricted to 78 games. In the subsequent year, a lumbar strain limited his playing time to 77 games. These injuries, coupled with the breakouts of Campbell and Anthony, pushed Mayer down in prospect rankings.

I’ll fully admit that at the start of spring training, I was a Mayer doubter. The injuries pushed him off my radar and I thought Campbell would break camp with a hot bat. However, Mayer’s performance in spring training has made me reconsider my previous beliefs.

Mayer mashes fastballs, but has had some difficulty handling sliders and other breaking pitches. On February 27, the Red Sox played the Tigers in Lakeland. Mayer faced two major league pitchers, Kenta Maeda and Jack Flaherty. In the first inning, he knocked a triple off Flaherty’s slider. Later in the game, he hit a home run off a Maeda fastball. 

These aren’t minor pitchers who are at camp for a cup of coffee. Flaherty is coming off a World Series win with the Dodgers. His improved 2024 slider yielded a 36.3% whiff rate and 27.1% strikeout rate. Maeda may not be the same elite pitcher he was with the Dodgers or Twins, but he remains a major-league starter. Mayer’s 3-for-3 performance against advanced pitching highlights his improved pitch recognition and bat-to-ball skills.

As for his defense, Mayer has recorded a 1.000 fielding average at shortstop across 13 innings and a 0.667 fielding average manning third base over 13 innings. Primarily a shortstop, Mayer only played two games at third between 2023 and 2024 in Double A, so the drop off in his positional fielding average isn’t shocking. If Mayer continues on his hot streak and manages to break camp with the Red Sox, where does he play? Ian Browne tweeted that Rafael Devers' anticipated spring training debut was pushed back. If Devers isn’t healthy by Opening Day, Alex Bregman will play at third. Drama aside aside, this is the best defensive alignment for the infield.

Barring injuries, Trevor Story will be the team’s starting shortstop. Story has dealt with a ton of bad luck during his tenure with the Red Sox. I hope he can finally manage to stay healthy for a full season. If Story can provide a full season with a .250 batting average, sharp defense, and 15 stolen bases, his WAR should hover between 3.5 and 5.0. 

This brings us to second base. David Hamilton is putting on a strong performance as is Vaughn Grissom. Both arrived at camp stronger and their defense looks sharp. Joe Weil from WEEI tweeted the following breakdown of Red Sox second base starts: 

Kristian Campbell’s spring training performance has been the weakest amongst the second base candidates and the Big Three. He’s put up some good at bats, forcing high pitch counts and drawing walks, but has only mustered one hit in eight games. At times, Campbell looks uncomfortable at the plate. After being named Baseball America’s 2024 Minor League Player of the Year, he’s under a tremendous amount of pressure. On the other hand, Mayer looks comfortable at the plate and on the field. He exudes the energy of a fresh-faced boy band frontman. Roman Anthony has a je ne sais quoi and looks as cool as a cucumber. 

A part of me wonders if Campbell is getting the Blake Swihart treatment from the organization. Selected in the first round of the 2011 MLB Draft, Swihart was a top-ranked catching prospect who was pushed into a utility role by Sandy Léon and Christian Vázquez. Drafted as a second baseman, Campbell underwent reps in the outfield, shortstop, second base, and third base last year. Moving around the field positionally didn’t affect his offensive performance in the minors.  After Mayer went down with an injury, Campbell moved to shortstop so he only played two games at second base in Triple A. This indicates some sort of oversight on the organization’s end. Going into camp, it was heavily implied that second base was open for Campbell to take, despite the fact that he didn't spend much time at second in the previous season. 

Smart organizations value positional versatility, just look at the Dodgers. Manager Alex Cora is a huge proponent of versatility and athleticism. Campbell is only 22 and still has time to develop. All things considered, the arrival of Alex Bregman should alleviate some pressure to perform. There’s no harm in starting Campbell at Triple A to work on his infield defense and calling him up if and when an injury occurs.

In a recent interview with Rob Bradford on the "Baseball Isn’t Boring" podcast, Mayer stated, “Wherever I get the opportunity to play, that’s where I’m willing to play.” His athleticism should make for a “smooth” transition to second. Talk Sox contributor, Nick John, posted some videos of Mayer taking some ground balls at second during practice.

Transitioning from shortstop to second isn’t unusual. After the Phillies signed shortstop Trea Turner, shortstop Bryson Stott shifted to second base and was nominated for a Gold Glove in 2023 and 2024. Mayer is a decent comp for Stott. Both former first round draft picks are left-handed hitters with similar builds and minor league stats. 

The infield logjam of Hamilton, Grissom, and Mayer is a good problem to have. Last season, fans witnessed the team’s infield defense fall apart after Story went down early. Injuries happen, and you can’t have too much depth. If Hamilton, Grissom, and Mayer keep playing well over the next two weeks, I think it opens the door for a trade discussion. 

Looking at Hamilton’s splits from last year, his offensive production wasn’t consistent. 

Hamilton’s stats suggest that he may not be able to sustain this level of performance over the course of a 162-game season. While he’s valuable as a late-innings pinch runner, he’s not an everyday starter. A left-handed hitter, Hamilton has a career 43 wRC+ against left-handed pitching. With left-handed prospects like Mayer and Anthony making strides in camp, Hamilton could become the odd man out. If he continues to perform well during spring training, now would be the ideal time to sell high on him.

The 2025 roster is supposedly set in stone, but there are a lot of uncertainties surrounding the pitching staff. Kutter Crawford likely will start the season on the IL and Brayan Bello is drifting in the same direction. Lucas Giolito is slated to make his spring training debut this Thursday, coming off his UCL repair surgery. Tanner Houck and Garrett Crochet have made solid outings, but are returning after career-highs in innings last season. Walker Buehler seems locked in and ready to pitch, debuting his new high socks.

In the recent "Talk Sox" podcast, we discussed how the bullpen could be worse this year.  The team lacks a go-to guy for the ninth. Aroldis Chapman showed his classic form versus the Twins. Liam Hendriks' performance was subpar. Justin Wilson gave up three earned runs in two-thirds of an inning against the Rays. Justin Slaten is a potential closer candidate, but he’s young and needs some more experience before becoming a closer.

Bob Nightengale reported that the Padres are still open to trade offers for Dylan Cease and Michael King. I propose the following trade package: Kutter Crawford, Cooper Criswell, David Hamilton for Robert Suárez and Dylan Cease. 

Suárez solidifies the bullpen and alleviates the pressure for Hendriks and Chapman to perform. A six-man rotation of Garrett Crochet, Tanner Houck, Dylan Cease, Walker Buehler, Brayan Bello, and Lucas Giolito would be one of the best in baseball. There's no such thing as having too much pitching depth. Speaking of which, Quinn Priester and Richard Fitts look great in camp and could step up as spot starters when needed. I could also see Richard Fitts taking over Cooper Criswell’s long-innings reliever role in this scenario. 

Next year’s free agent starting pitching class is strong, but there’s no harm in being proactive. Notably, Cease is a Scott Boras client. The Red Sox aren’t averse to working with Scott Boras - newcomer Alex Bregman is represented by him. Over the past two offseasons, Boras has shown signs of slowing down. Pete Alonso and Corbin Burnes didn’t sign the megadeals that they initially targeted. For what it's worth, Cease is on record as saying Fenway is his favorite road stadium. Craig Breslow brokered a savvy deal with Alex Bregman and could do the same with a short-term, high AAV extension for Cease.

Once Marcelo Mayer returns from his the stomach illness making the rounds through camp, it would be worthwhile to see him get some reps at second base. Campbell has played more games in left field than at second during spring training, so he might see additional time there in the minors, allowing Mayer to gain experience at second. If Trevor Story gets injured, Mayer’s path to the major league roster becomes clearer. Later in the season, a potential platoon between Grissom and Mayer at second could also be a possibility.

There are a ton of permutations for the Red Sox’s infield this year. With Mayer, Grissom, and Hamilton making a strong case to join the major league roster, the infield depth presents a positive challenge for the front office. As spring training progresses, fans should have a better grasp on the infield’s alignment for Opening Day and beyond.