Brayan Bello's Struggles Won't Be Easily Fixed By A New Red Sox Coaching Staff

To say the beginning of the season has been an absolute disaster for Brayan Bello could almost be considered an understatement. The 26-year old righty was hoping to build off a solid 2025 while positioning himself as a crucial piece of the Boston Red Sox’s rotation behind Garrett Crochet, Sonny Gray, and Ranger Suarez. Unfortunately for him, he’s currently sitting on a 9.00 ERA after his blow-up start against the Orioles with a measly 13.0% strikeout rate to go along with an 11.3% walk percentage. His FIP has shot up to 8.27 to pair with a -0.6 fWAR. As a long time Bello Believer (trademark pending), I wanted to take a look under the hood and see if we could explain what’s going on with the young, former Opening Day starter.

Maybe the most glaring thing is that Bello has all but scrapped his four-seam fastball. While it was never a pitch he favored, it’s taken a significant step back behind his other options, including a new curveball, so far in 2026. In 2025, he threw the four-seamer 15% of the time and averaged 95.1 MPH on it. Now, that percentage has dipped to 3% and it’s lost some gas at 93.7 MPH. This could be, in part, due to pitching coach Andrew Bailey’s preferred use of off-speed and breaking pitches, but the last time that happened in 2024 Bello was vocal about reintroducing the pitch back into his mix and it helped to turn his season around. From the outside looking in, it seems more like Bello no longer trusts the pitch and that has taken away a lot of his grip-it-and-rip-it style of pitching. That style though, is what his career has been built on. He’s been at his best when he just pitches. Now, he seems to be trying to nibble on the edges of the plate too much and he’s being crushed as a result. That’s not the only reason for concern, though.

Bello has raised his arm angle a staggering 10 degrees, from 33 degrees in 2025 to 43 degrees this season. If you compare pictures or videos from previous seasons to now, it’s fairly noticeable. While there are merits to raising the arm slot, none of them have really panned out for Bello. It is likely what has contributed most to his massive uptick in generating whiffs, up from 20.1% last season to 31.6% now, but it’s also leaving him vulnerable to his sinker playing a lot higher in the zone than intended.

We saw the results of that against the Orioles, when Adley Rutschman took a 95 mph sinker that hung out high and inside to deep right field. To be fair, Bello gave up home runs on his cutter and four-seam fastball as well, but the sinker got crushed all night because it failed to sink at all. That flat action on all of his pitches is a direct result of his raised arm angle as well. While the raised arm slot would work, or should work, for a four-seam fastball because the angle causes it to ride more, it has the opposite impact on the sinker.

As we know, Bello is a sinker-heavy pitcher so such a drastic, upward change in his arm angle makes the pitch less effective. It also takes the sweeping motion away from his sweeper and forces him to rely on that new curveball as a snappier breaking ball. We can see an obvious difference if we look at his movement profiles from 2025 and 2026 side-by-side. His changeup and sinker are living in the same zone again this season, but when the velocity is down on the sinker, almost a full mile per hour from 95.3 to 94.4, then the pitches don’t play off each other nearly as well as they did last season. His four-seamer gave hitters a different look last season but now, when he does throw it, it’s cheating into the same movement profile as his sinker. Flattening out his arm angle could do wonders for him, and there’s been some tinkering from start to start recently, but we’ve yet to see it pay any true dividends. 

Also contributing to the issue is that Bello has lost spin rates on each of his pitches, and some have a fairly significant drop-off. His sinker is down from 2,121 RPM to 2,036 RPM, his cutter from 2,479 RPM to 2,333 RPM, the four-seamer from 2,161 RPM to 2,056 RPM, the sweeper from 2,476 RPM to 2,335 RPM, and his changeup is down from 1,842 RPM to 1,696 RPM. Yes, he’s working with a much smaller sample size so far this season, but the decrease in revolutions per minute is concerning. That spin allows the ball to break how it’s supposed to. It helps aid in the “ride” the four-seam is supposed to have and is what forces a sinker to dive as it’s reaching the plate so the hitter swings over the top of it. Now though, a lot of his pitches are living in the same RPM realm and it’s causing them to bleed into one another as they approach the plate. The sweeping action is less on his sweeper, down from 9.9” of glove-side break to 7.2” of glove-side break, and his cutter is almost running completely flat in 2026 as it has dropped from 0.9” of glove-side break to a measly 0.2”. Without the spin on each pitch, likely due to the increased arm slot, Bello goes from a groundball-inducing sinkerballer to someone who can't aggressively attack the bottom of the zone. This makes every other pitch in his arsenal far less effective as a result.

I won’t go so far as to say that the Brayan Bello we got in the second half of 2024 and most of 2025 is gone, but it’s looking like that version of him is very lost right now. Might he benefit from a stint in Worcester to get his mechanics back on track> If the rotation were completely healthy, that’d be an easy enough decision. With Johan Oviedo on the 60-day IL and Sonny Gray on the 15-day IL, though, it’s a bit easier said than done.

Once Gray comes back (Alex Cora gave a positive update on him before being ousted), then a much tougher conversation is likely going to happen than what happened on the mound during Bello’s start. Rookie Payton Tolle looked absolutely dominant against the Yankees in his season debut. He was electric and brought an energy to the team that they’ve needed since the season started. Perhaps he (and fellow rookie Connelly Early) can keep pitching well enough to buy Bello a little time to get his A-game back.