4. Cal Quantrill
Even though the 2023 MLB season didn't go the way that the Guardians planned, they still had some things worth being proud of. One of the bright spots was the starting rotation finishing with the ninth-best ERA in the Majors (4.09).
You know who could've made that number better had it not been for his poor play? Cal Quantrill.
After going 15-5 with a 3.38 ERA across 32 starts in 2022, Quantrill finished his latest MLB campaign with a 4-7 record, 5.24 ERA, and 1.465 WHIP in 19 appearances. It didn't help that he allowed at least four earned runs in five or fewer innings seven times.
For reference, he only did that once in 2022.
Although a shoulder injury likely played a role in his underwhelming numbers, that doesn't change the fact that Quantrill is on thin ice. If he can't prove to Vogt and the rest of the coaching staff that he can get back to his 2022 form, the Guardians are better off seeking a more consistent arm for the rotation.