The Boston Red Sox have not always had the greatest track record at starting pitcher development. While players like Jon Lester, Eduardo Rodríguez and even Clay Buchholz turned into reliable starters (with Lester a level above that), the Red Sox’s best starting rotations of the last few decades have been built more on trades and free agent signings than through the draft and development (and even E-Rod came to the team as a nearly finished product).
Brayan Bello is the latest would-be homegrown ace for the organization, and prior to making his MLB debut earlier this season, Red Sox homers weren’t the only ones believing. Bello, who signed out of the Dominican Republic in 2017, built up quite a reputation as he rose through the minors the last few years thanks to his electric fastball/slider combination and strikeout rates that looked like they belonged to an All-Star closer instead of a starting pitcher. His star rose particularly quickly earlier this year, as he made the leap from strong prospect known in Red Sox circles to a great prospect who had the attention of a larger swath of talent evaluators. As his legend grew, so did his ranking among the prospect set. Currently, Bello is ranked the 38th best prospect in baseball by FanGraphs, slotting in as the No. 3 prospect in the Red Sox’s recently improved system.
Due to the rapid ascent Bello made up the prospect rankings, when he got the call to make his first MLB start on July 6 this year, it was a big deal — especially since the Red Sox were still playing for a postseason spot at that point, albeit nominally. Bello didn’t get an easy assignment in his first start, as he was tasked with taming the Tampa Bay Rays, who rank 11th in wRC+ among MLB teams this season. The right-hander was a little shaky in that first start, allowing four earned runs on six hits and three walks over four innings while only striking out a pair of batters. Things got worse from there, with Bello getting lit up for five runs in back-to-back starts against the Rays and Toronto Blue Jays.
Alex Cora then opted to demote Bello to a degree, tasking the rookie with pitching in relief in his next two outings. It was a certainly a quick hook from Cora, with Bello only getting three starts to prove himself, but, in fairness, the results weren’t there. Unfortunately, Bello didn’t have much time to work himself back into a rotation role before he was sidelined with an injury for three weeks in August.
When Bello came back to the team, Cora inserted him back into the rotation, with Bello making his first start since the injury on Aug. 24. And, you know what? That start went really well. Bello struck out seven batters while allowing two earned runs over five innings against the Blue Jays, and while it didn’t lead to a win, it was a very pleasant surprise. Bello has made three more starts since then, and overall, his post-injury production has been pretty good, if not great, highlighted by six shutout innings against the Texas Rangers on Sept. 3. Putting those four starts together, Bello has a 3.54 ERA, 2.38 FIP and 25 percent strikeout rate in his last 20 1/3 innings. While that strikeout rate doesn’t come close to the marks of 30% and higher he regularly posted in the minors, it’s a step in the right direction, especially as he had just a 17.2 percent strikeout rate in the first 17 innings of his professional career (as well as an 8.47 ERA).
Now, as always, it’s dangerous to try to project anything off of a handful of starts, so I’m not here to say Bello should be etched into the Red Sox’s starting rotation for the next 15 years. But the incremental progress is a least a positive sign. So what’s Bello done to turn things around?
At a surface level, as we discussed earlier, Bello has been able to punch batters out more effectively. Strikeouts are a big part of his game, so when he isn’t getting swings and misses, he’s simply not going to be as successful. In addition, Bello has been more effective with each of his pitches, especially his changeup. In his first stretch of starts before his injury, Bello’s fastball, slider and changeup were all pretty weak, with negative marks in runs above average for each offering. Since returning from his injury, his fastball and slider have been hovering just above zero, but his changeup has really proven to be effective at 3.6 runs above average. To his credit, Bello is seeing those results and applying them to his approach, as he has thrown his changeup more than two percent more often in his last four starts than he did earlier in the season.
Interestingly enough, as Bello has started getting more strikeouts and finding a better pitch mix, he’s actually been hit harder than earlier in the season, allowing an average exit velocity of 89.5 miles per hour and a barrel rate of 11.1 percent during the last four starts compared with marks of 86.6 percent and 3.4 percent in the five outings prior. In addition to that troubling underlying data, Bello is still erratic with his command, as he has walked 10.7 percent of the batters he’s faced in the last four starts, which is technically down from his first five outings (12.6 percent) but is still far higher than it should be. Elevated walk rates have been a through line of Bello’s career and improving on that front will be a key to his long-term development.
All told, Bello’s 2022 season has been a mixed bag, with some glimpses of greatness mired by plenty of shortcomings. Four starts doesn’t mean all that much in the grand scheme, and Bello still has a lot of improving to do, but Bello has at least begun to illustrate why he’s such a can’t-miss prospect in the first place.