PITTSBURGH -- Mitch Keller felt like any other pitcher grinding his way into early August.
The veteran starter struggled through the first four months of the year and was fatigued, but saw hope for a strong finish down the stretch. Then suddenly, in his 22nd start of the year on a rainy Sunday in Cincinnati, Keller began to feel tightness that worsened throughout the afternoon.
Before he knew it, his day and season were over.
Keller finished the year with a 5.29 ERA after going on the 60-day injured list on Aug. 3 with a right arm teres major muscle injury. The longest-tenured Pirates player was forced to watch the final two months of the club’s best season since 2018 from the dugout as he recovered.
Keller didn’t undergo any procedures and told MLB.com on Sept. 23 he expected to begin throwing again at the end of October and have a “normal offseason.” Though after the difficult season, questions loom over Keller’s future with the club, as the team has four younger and potentially more cost-effective starters coming off strong years, while Keller couldn’t find his groove.
“It was kind of a weird year, honestly. I didn't really feel like myself or feel 100% the whole year,” Keller said. “So I was just not trying to be too hard on myself, just because I didn't feel like myself or the best I could.”
“I think there was definitely some positives throughout the year, early in the year, and then just some learning things to go through. Health-wise and stuff hindered my ability to be the best I could be out there. So I'm just looking forward to next year being 100% healthy and just being on a confident track.”
It’s not often you hear of a teres major muscle injury. Keller described the feeling as cramping or tightness in the armpit area. The muscle is known as the “lat's little brother,” an internal rotator running parallel to the better-known lat muscle. It connects the shoulder blade to the humerus, making it an obvious muscle that needs to be at full strength for a pitcher.
Keller suffered what is believed to be a Grade 3 strain, where the muscle is torn off the humerus. The 30-year-old didn’t undergo surgery and instead shut it down for the season. At the end of the year, Keller said he felt completely healthy and was progressing strength-wise.
Keller couldn’t pinpoint an exact time when he felt the injury occur, but his season wasn’t going in the right direction before he went on the injured list. When reflecting on his year, he pointed to spots in his mechanics he had been at in the past but lacked in 2026.
Keller has been a key cog in the Pirates’ organization over the last decade. He was drafted in the second round in 2014 out of Xavier High School in Cedar Rapids, Iowa. From there, he debuted at 23 in 2019 and pitched to a career-high 194 1/3 innings and an All-Star appearance in 2023.
Ahead of his second consecutive Opening Day start in 2024, Keller inked a five-year, $77 million extension, the largest deal the franchise has ever given to a pitcher. His deal is structured to increase his salary over the course of the contract, moving from $16.9 million in 2026 to $18.4 million in 2027 and $20.4 million to finish out the deal in 2028.
As Keller’s salary grows, the same goes for the rest of the Pirates’ rotation. Young starters Paul Skenes and Jared Jones are arbitration-eligible for the first time, and both produced alongside Braxton Ashcraft and Bubba Chandler throughout the year.
Keller is an important veteran presence in the rotation and clubhouse. And he’ll need a major rebound to return to form.
“First and foremost is just getting healthy and being in a spot where I feel like I can make some good improvements out there,” Keller said. “It was a grind of a season for me in a lot of ways, but just trying to find the positives in it and then getting healthy and just being strong for next year.”