2. Tanner Houck
An inconsistent starting rotation was one of the Red Sox's biggest issues in 2023. Boston's starters accounted for 56 of their losses — 9th-most in the MLB — while combining for a 4.68 ERA (9th-worst).
While each starting pitcher played a part in the underperformance, Tanner Houck was one of the biggest culprits. He was one of two Boston SPs with double-digit losses this season (10), however, Brayan Bello at least had a positive win percentage (52.2%) while Houck clicked in at 37.5%.
The 27-year-old was once the one of the Red Sox's highest-rated prospects, but that seems like a distant memory. Not only is Houck coming off a career-worst 5.01 ERA in 21 starts, but he also also gave up up 3.5 walks and 1.2 home runs per nine innings.
It isn't like the Red Sox didn't try to help him win. After all, the team scored an average of 5.46 runs across his appearances.
Considering how Boston has been linked to free-agent arms like Marcus Stroman and Japanese ace Yoshinobu Yamamoto, I won't be surprised if Houck is pushed out of the rotation this offseason. If he's still in Beantown come April, it's going to be tougher for the Red Sox to be an above-.500 club.