How an increase in fastball velocity is helping Chicago Cubs reliever Brad Keller find success

Chicago Tribune

24-05-2025

CINCINNATI — Brad Keller grinned at the mention of his fastball velocity.
After his four-seam fastball sat at 93.8 mph last year, Keller's heater is averaging 97 mph with the Chicago Cubs. The dramatic increase hasn't escaped Keller's attention. He topped it out at 100 mph on a 1-2 pitch to the Los Angeles Dodgers' Teoscar Hernández with the bases loaded and nobody out in the seventh inning April 22, attempting to hold the Cubs' two-run lead.
'It's sick — I surprised myself a couple times, like hitting 100, never thought I would ever do that,' Keller told the Tribune. 'It's pretty cool, but it's fun going after guys now instead of like before just relying on movement, things like that, in the zone. Now I still have the movement, but with added velo, just a little bit more confidence to be in the zone attacking guys and see what they can do.'
Some of it has to do with usage, tapping into more velocity out of the bullpen in shorter stints rather than needing to reserve enough as a starter to get through multiple innings, and smoothed out mechanics. But perhaps the biggest centers around Keller's health.
Keller, 29, was diagnosed with thoracic outlet syndrome (TOS) in 2023 and underwent surgery after that season. The mental impact of finally getting a diagnosis after months of unknowns at what was causing his sudden and seemingly random inability to throw a baseball was as much, if not more, of a relief than from the physical ailments he dealt with that included being unable to grip a baseball and intense shooting pain deep into his right armpit that ultimately required surgery. Keller was told by doctors he likely had been pitching through varying symptoms of TOS as far back as 2020.
Now healthy and after his first normal offseason in years, Keller is thriving with the Cubs. Entering the series opener Friday against the Cincinnati Reds, Keller owns a 2.70 ERA with a 1.029 WHIP, career-best 3.43 strikeout-to-walk ratio and 148 ERA+ in 21 appearances spanning 23 1/3 innings,
'Over the last really three years or so just battling the TOS and everything with that, just not really feeling great when going out there, but I think that I'm finally feeling healthy, feeling like I'm bouncing back well after outings,' Keller said. 'Us bullpen guys, we want to be available every single day to obviously help the team win. And so I wasn't sure how my body would respond to something like that because I've never done it before, and so I'm really happy with how I've been able to stay in a good routine, to stay healthy and feel good every single day.'
There are encouraging trends for the right-hander beyond the significant jump in velocity.
Keller has the highest Whiff% (24.7%), 1st Pitch Strike% (64.5%) and Chase% (32.5%) of his career, all of which highlight how his success isn't rooted solely on his four-seam fastball's improved velocity. A more effective slider has played off well against the fastball. Hitters produced a lot of damage off Keller's slider in 2024, tagging it for four doubles, five home runs and a .581 slugging percentage. This year, Keller is throwing his slider 13% less and seeing less hard contact, extra-base hits and slug (.286) while increasing his sweeper usage by 8%, a pitch he started using in 2023 that is 1-for-19 against.
'I think that's every pitcher's dream is to add velocity like that and kind of organically do it, really,' manager Craig Counsell said. 'And I think he's gotten better in some other areas too. … It's credit to Brad and our staff. They've collectively done a great job working together, getting him to a good spot and a spot where he's really confident. You watch him go out there, and it's really good stuff. Couldn't be happier with where Brad's at.'
Counsell remembers speaking with Keller a lot over the winter trying to recruit him to sign with the Cubs, which he did on a minor-league deal with a camp invite before being added to the big-league roster before the start of the season. Keller has become a versatile arm for Counsell, especially as the Cubs have navigated injuries to the pitching staff early in the season. They gained a veteran reliever Friday with the return of right-hander Ryan Brasier from the injured list and optioned right-hander Ethan Roberts to Triple-A Iowa.
Keller, who first debuted in the majors at 22 with the Kansas City Royals in 2018, is the type of high-upside pitcher the Cubs have needed to find out of the bullpen.
'He's got so much career ahead of them, I think one of just really emphasizing that to him about how much he's got left in terms of as a pitcher, and that I love players that have accomplished a lot at a young age,' Counsell said. 'I think that means it's in there. And injuries and other factors can derail you, but that means that success is in there and fortunate that he chose us to be the ones to help him get it back going the right way.'