Why the Astros' New Southpaw Could Be a Sneaky Impact Move

Astros are still in the mix of signing players, as lefty Tom Cosgrove is now added to the organization.

San Diego Padres pitcher Tom Cosgrove (59) throwing a pitch | Kirby Lee-Imagn Images

The Houston Astros keep making moves. Per Brian McTaggart, lefty Tom Cosgrove has signed a minor league deal with the Astros with an invitation to spring training. If Cosgrove makes the majors, he will earn a guaranteed salary of $900,000.

Source: LHP Tom Cosgrove signs with the Astros on a Minor League deal with invite to Spring Training. He’ll make $900,000 if in the Majors. Reliever has pitched in 74 big league games, mostly with the Padres.

— Brian McTaggart (@brianmctaggart) January 30, 2026

More Lefty Insurance

The agenda behind this signing is to add more lefty insurance to the bullpen. Last season, two of the Astros lefties in Josh Hader and Bennett Sousa fell to injuries mid-way which ended their season. Houston's best-case scenario falls within the case of Cosgrove making the majors and being added as the fifth lefty to the Astros bullpen, next to other southpaws Steven Okert, Bryan King Sousa, and Josh Hader.

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Hader's in year three of his massive five-year deal and both Sousa and Okert avoided arbitration, settling for one-year deals in 2026.

Cosgrove's career spans 74 MLB games for the San Diego Padres and Chicago Cubs. A Staten Island native, the 29-year-old has a career ERA of 3.86 in 70 innings. 2023 was the last year he pitched a substantial amount of games and was exceptional, with a sub-2 ERA in 51.1 innings and a WHIP under 1.00, scattering just 31 hits, holding batters to a .173 AVG.

Massive Sophomore Slump

San Diego Padres relief pitcher Tom Cosgrove walks to the dugout | Orlando Ramirez-Imagn Images

Something completely changed for the worse the following year, however, as they often do for relievers. In just 18 games, Cosgrove got rocked, posting a double digit ERA over 11, surrendering 19 runs in 14.2 innings. His hard hit climbed to 38% with batters hitting .354, mashing baseballs off him like All-Stars. 2024 was like night and day in all the wrong ways for him, unable to get batters out like he did so well in the previous season.

Hoping to put 2024 behind him, Cosgrove was traded to Chicago in the beginning of the 2025 season, a season where he barely made a mark in the Cubs bullpen pitching just four appearances. While the ERA is just 2.25, the sample size is short, making little to no impact. The Cubs had him spend most of 2025 in Triple A Iowa.

Astros Give Cosgrove a Chance

Astros general manager Dana Brown loves these kinds of pitchers. One who clearly has talent and at one point in their career dominated for a period of time until the dominoes fell. Cosgrove's rookie season was clearly his best year, and the Astros believe they can get him back to those numbers.

Looking at advanced metrics, both 2023 and 2024 percentages on ground balls and ground ball to fly ball ratio are roughly the same. The main issue is line-drive percentage, which ticked up by 15% in his sophomore season.

Based on his sudden 2024 meltdown, the newly added southpaw needs to locate his pitches better. He doesn't throw hard (88-90mph on his fastball), but was successful in his first year due to his lower arm slot to catch hitters off guard.

King and Okert Had Similar Outcomes

There's a positive track record for relievers like Cosgrove if they implement themselves in the Astros pitching development. Last year's relievers in King and Okert both had phenomenal years and were pretty much overlooked before Brown took a chance on them.

Before the Astros selected King in the Rule 5 draft of 2022, it was unclear if King would even make his MLB debut due to a previous elbow surgery. Fast-forward to now and he's been nails since his debut in 2024 as the seventh inning guy behind teammates Bryan Abreu and Hader.

Okert more or less has performed the same results. 2025 saw the 34-year-old with a career-high in games (68) and doubled his innings pitched from 2024. Last season Okert pitched 71.2 innings attuned to a 3.01 ERA and a 2.76 FIP.

A drastic improvement from relief pitchers on a new team isn't just getting lucky. Over the last decade, the Astros’ pitching department has turned many run-of-the-mill relievers into instant contributors. Cosgrove looks to be in that mix.

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