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The Giants are taking a one-year gamble with the injury-prone Tyler Mahle after a solid 2025 season in Texas.

The San Francisco Giants continue to fill out their rotation. Per the San Francisco Chronicle‘s Shayna Rubin, the club is closing in on a one-year deal with right-hander Tyler Mahle.

Mahle, 31, enjoyed a bounce-back season with the Rangers in 2025. In 16 starts, he pitched to a 2.18 ERA in 86.2 innings in Texas. He missed three months with a rotator cuff strain.

Advanced run-prevention metrics aren’t quite as bullish on Mahle’s work in 2025. His 3.37 FIP looks good at first glance, but it’s carried by a 4.9% home run per fly ball rate. His xFIP and xERA sit at 4.43 and 4.37, more in line with a bottom-of-the-rotation starter.

What Tyler Mahle’s Signing Means for the Giants

GettyThe addition of Tyler Mahle should give the Giants a reliable No. 3 starter behind Logan Webb and Robbie Ray.

Mahle becomes the second rotation signing for the Giants this offseason. The club inked former Rays right-hander Adrian Houser to a two-year deal on December 19. The two join a rotation headlined by Logan Webb, Robbie Ray, and Landen Roupp.

Roster Resource currently projects Mahle and Houser to be the Giants’ No. 3 and 4 starters. The pair presents stable options at the bottom of the rotation, even if there isn’t much upside. That gives them a hedge in case prospects Blade Tidwell and Carson Whisenhunt need more time in Triple-A. Tidwell was named the Giants’ top breakout candidate by MLB.com’s Maria Guardado.

Mahle’s injury history should give the Giants some pause. In addition to the shoulder issues that plagued him the past two seasons, he also underwent Tommy John surgery in 2023. He’s only made 30 starts once in his career (2021), and hasn’t logged more than 120.2 innings since. Having Tidwell and Whisenhunt gives San Francisco quality internal options in case Mahle suffers another injury.

Other internal options on the 40-man roster include Kai-Wei Teng, Trevor McDonald, Carson Seymour, Hayden Birdsong, and Keaton Winn. It’s more likely that some of these pitchers could be converted to a relief role simply due to the lack of rotation spots.

What’s Next for the Giants?

The Mahle and Houser signings represent the Giants’ additions this offseason so far. The team was linked to Framber Valdez, but the club’s latest rotation addition likely means they’re out on the former Astros ace.

Second base remains a priority for the Giants. Former prospect Casey Schmitt is currently projected as the starter, but he owns a career .228/.283/.384 slash and 0.6 fWAR. Despite ample opportunities, his bat has not developed at the major league level. Considering his career track record, the club should not rely on him to hold the position in a competitive National League West.

One realistic option the Giants could consider is St. Louis Cardinals‘ utility infielder Brendan Donovan. With Matt Chapman and Willy Adames entrenched on the left side of the infield, and Heliot Ramos in left field, Donovan would strictly play second base in San Francisco. The left-handed hitter has a .282/.361/.411 career slash and a 119 wRC+. His 119 mark from 2025 would have ranked second on the team behind Rafael Devers.

Acquiring Donovan gives the Giants a reliable on-base threat in front of Adames, Devers, and Chapman. The trio combined for 71 home runs last season. The price to land Donovan from the Cardinals is high, demanding top prospects. Katie Woo and Ken Rosenthal of The Athletic reported on December 13 that St. Louis inquired about Jurrangelo Cjintje and Lazaro Montes in a potential Donovan trade to the Seattle Mariners.

Michael McDermott Michael McDermott is a writer at Heavy Sports covering the Arizona Diamondbacks and Major League Baseball. Michael has 10 years experience writing about the D-backs and their farm system for AZ Snake Pit, Burn City Sports, and Diamondbacks On SI. More about Michael McDermott