Grading the SF Giants back-end starters in 2025

Outside of the SF Giants four starters who spent the majority of the year in the rotation, San Francisco received contributions from a variety of other starting pitchers who filled the back end of the rotation. Let's grade these back-end starters, with an eye out for who could be a long-term piece.

Grading the SF Giants back-end starters in 2025

Hayden Birdsong: D

The 23-year-old pitcher is still young enough that he can amount to something for the Giants in the future, but he did not perform great in 2025. He gave the Giants 10 starts with a 4.80 ERA and a 4-4 record. Overall, he was worth -0.5 bWAR, a downgrade from his 0.3 bWAR in 2024.

Jordan Hicks: F

Hicks was not as bad as the media made him out to be in 2024, when he finished with a 4.10 ERA across 20 starts and 9 relief appearances. In 2025, however, he struggled badly and never found his footing. In nine starts and four relief appearances for the Giants, he posted a 6.47 ERA and a 1-5 record, worth -0.7 bWAR.

Hicks went to Boston and was even worse, accumulating -1.1 bWAR and putting together an ERA of 8.20 in 21 relief appearances before landing on the injured list in early September.

Kai-Wei Teng: D

Kai-Wei Teng was arguably the best starter with the Sacramento River Cats this season. He appeared in eight games for the Giants, pitching to a 6.37 ERA with 39 strikeouts and 17 walks across 29.2 innings. Teng may not have the command to stick in the rotation, but he has the stuff to strike out major league hitters. That can lend itself to a bullpen role.

Carson Whisenhunt: C-

Whisenhunt, one of the club's higher-rated prospects going into the season, was decent across five starts with the big league club. He went 2-1 with a 5.01 ERA, but tossed only 23.1 innings, averaging less than five innings per start.

Carson Seymour: D

Seymour made three starts and 13 relief appearances in his rookie season in 2025. He was decent, with a 4.75 ERA, though his 6.11 FIP indicated worse peripheral numbers. Seymour allowed nine home runs in 36 innings with San Francisco.

Kyle Harrison: C

Harrison only started four games before being traded to Boston as part of the Rafael Devers trade. Still, he helped the club trade for a generational offensive player, so he did his part.