2025 Player Profile: Mitch Keller

1/28/25 – Ethan Smith – @mvp_EtHaN / @LockedOnPirates

Mitch Keller has been a staple in the Pittsburgh Pirates rotation since his debut season in 2019, and be it for better or for worse, Keller has overcome numerous obstacles to place himself in the position he is in today.

Prior to the 2022 season, Keller was one of the worst pitchers in MLB, but since then, Keller has become the workhorse of the Pirates starting pitching staff, earning Opening Day starter honors in back-to-back seasons, the first time a Pirates starter earned such honors since Francisco Liriano started three consecutive Opening Day’s from 2014-2016, and even a lengthy contract to keep Keller tied to the Pirates until 2029.

For better or for worse is tried and true when it comes to Mitch Keller’s career arc, and when focusing on 2024, the same can be said, as last season was an up-and-down campaign for Keller, who was coming off an All-Star appearance in 2023.

Keller tossed 178 innings in 2024, tallying a 4.25 ERA with 166 strikeouts in what was Keller’s second highest workload season of his career, taking a short step down from the 194.1 innings he threw in 2023.

Prior to August 3, Keller had been dominant, posting a 10-5 record with a 3.20 ERA, seeming to fully cement himself as a top of the rotation starter in this league and becoming more than worthy of his contract extension. Trouble came for Keller though in his final nine starts, as he went 1-8 and allowed 37 earned runs in just under 46 innings, which led some to point to a trend over the past two seasons, where Keller’s second halves was not nearly as impressive as his first halves, seeing his ERA inflate in 2023 and 2024 after the first half concluded.

So, heading into 2025, how does Keller avoid these late season slumps?

For starters, maintaining his fastball velocity throughout the entirety of the campaign has to be at the top of the list for Keller. Take a shaky start last season versus the Reds on September 20 for instance, a start that saw Keller’s fastball clock in at 92 mph on average, which was his lowest total in a start in nearly three seasons to that point.

You could find plenty of other instances where Keller’s velocity dropped, and his ERA suffers from it considerably. Keep in mind that Keller does have three fastball offerings, a fastball, a sinker and a cutter, which is used in limited spurts, so Keller has the offerings to keep hitters off balance, considering his sweeper has become a strong strikeout pitch, but the velocity has to stay consistent for those pitches to work in tandem together, and across the past two seasons, that just hasn’t happened.

Another concern was the walk rate for Keller post-All-Star break, as prior to the MidSummer Classic, Keller had walked only 30 batters across 114.1 innings. After though, Keller allowed 20 free passes in 63.2 innings, a much worse walk rate. Keller still ranked highly in walk rate, ranking in the 73rd percentile on StatCast(6.5-percent), but limiting walks late in the season should be another major point of emphasis for Keller as well.

Sticking with StatCast for a moment, another metric to highlight is Keller’s whiff rate. Keller definitely forces his way to a ton of strikeouts, having 210 and 166 over the past two seasons, but Keller ranked in the 30th percentile and lower as far as whiff rate is concerned, and although his chase rate increased from the 26th percentile to the 47th percentile from 2023 to 2024, its an indicator that Keller has to miss more bats and induce swings out of the zone.

This all sounds bad for Keller, it does, but Keller has shown and proven his worth as a top-end starter, he just has to find a way to do so over the entirety of a campaign, something he has been unable to truly do over the course of his career.

Keller will enter 2025 as apart of a top trio that will also feature Paul Skenes and Jared Jones, and with Keller being the most established of that group, his expectations heading into 2025 should be lofty, especially with the money the club has tied into him.

If Keller can maintain his strong velocity over the course of the season and utilize his sweeper and all of his fastball offerings at a plus-level, 2025 should be another solid year for Keller, but there is legitimate concern with how the second half could go based off the sample we’ve seen over the past two second halves.

Nevetheless, Keller will once again be fully cemented into the starting rotation, a group that has warranted upside, and Keller has proven he can play at an All-Star level before, so can he do it again in 2025? If he can, the Pirates may have one of the better pitching trios in baseball, and they’ll surely reap the benefits if that turns out to be true.