Astros should kick the tires on one of 2025’s most surprising breakout relievers

Restocking the bullpen is on the to-do list for all Major League teams during the offseason, and the Houston Astros are no different. If the 2025 season proved one thing, it's that if Josh Hader goes down with an injury, the Astros' bullpen looks completely different. Hader and Bryan Abreu are an elite tandem to close out games, but the Astros need to find a high-leverage reliever who can get outs in the middle innings.

Their search could lead to one of 2025's most surprising success stories. Brad Keller opened his Major League career as the mainstay of the Kansas City Royals' pitching staff, but he may have been forgotten about after dreadful stops with the Boston Red Sox and Chicago White Sox in 2024.

The Chicago Cubs made Keller a priority non-roster invite ahead of spring training this past season, with the team believing their infrastructure could unlock something. They didn't just unlock something in Keller; the Cubs turned him into one of the best high-leverage arms in all of baseball last season.

In 68 appearances out of the Cubs' bullpen, Keller posted a 2.07 ERA. When a veteran pitcher has that type of success, the expectation is that he was getting lucky. That wasn't the case for Keller in 2025; he was dominant in every sense of the word. Keller gained nearly 4 mph with his fastball, sitting at just under 98 mph. That increase in velocity, paired with his devastating slider, led to him striking out over 27% of the hitters he faced last year.

Brad Keller's electric 2025 season should have Houston Astros racing to sign him this offseason

Keller's success was with a Cubs team that traded for former Astros' reliever Ryan Pressly last offseason. And, yet, it was Keller who was closing out games for the Cubs in the playoffs in October, while Pressly was released by the team after the MLB trade deadline.

Now, Keller is a free agent and likely has pitched himself out of the Cubs' reach. The Cubs don't make it a priority to sign veteran relief pitchers to multi-year deals, and Keller certainly is in line for one this winter.

Keller should be on the Astros' radar this offseason. With Hader and Abreu already in the fold, the Astros don't need to be shopping for a closer--and teams in need of bullpen will likely gravitate toward the likes of Edwin Diaz, Devin Williams, Ryan Helsley, and Robert Suarez first. That could leave Houston in a prime spot to pounce on Keller.