10: John Schreiber, Boston Red Sox
The Red Sox bullpen in 2022 was, for the most part, pretty terrible, with a combined ERA of 4.59 ranking 26th in the Majors. The closer position in particular was very bad, with 11 different arms getting save opportunities, and 28 total blown saves over the course of the season. Amidst this chaos, John Schreiber came out of absolutely nowhere and put together a fantastic year. In 65 innings pitched, the 28-year-old righty posted a 2.22 ERA with a WHIP below 1.000 and over 10 strikeouts per nine.
Prior to 2022, Schreiber had pitched just 31.2 innings in the Majors and had a career 5.97 ERA, with most of his time coming in Detroit. In both 2021 and 2022 though, he had dominated in Triple-A for the Red Sox to the tune of a 2.52 ERA over 78.2 innings, and since they were pretty much out of options, he was given a shot in the bigs. His pitch mix consists of a slider, fourseamer and sinker, all of which are pretty good and produced an xwOBA around .240, along with an occasional changeup, which is by far his weakest pitch. He's got average velocity and movement on all his pitches, but his sidearm angle can be tough for batters to deal with and keeps the ball out of the air.
The Red Sox signed a big-name reliever who'll be featured a bit higher on this list to lock down the closer position this offseason, so Schreiber will most likely be in a setup role this season which could be good for him since he blew three of his 11 save attempts last season. He had 22 holds in 2022, and if he sticks in that role for the full year, he could really solidify himself as one of the better bullpen arms in the division.