2) Adam Ottavino
The Red Sox acquired Adam Ottavino in a salary dump with the Yankees in the 2020 offseason. He was coming off an abysmal year in the short season, and was supposed to play a key role adding a boost to a bullpen than needed it.
Ottavino's year in Boston featured its ups and downs. He had a dominant first half but really struggled down the stretch. Fortunately, those struggles did not trickle into the postseason as he allowed just one run in his five outings, albeit in low leverage.
The right-hander moved onto play for the other New York team after that one season with the Red Sox and put together back-to-back quality seasons with the Mets. His flaws remain glaring, but when he's on, he's very good.
The 37-year-old possesses one of the nastiest sliders in all of baseball even with a bit of a decline in stuff overall, and also held the opposition to a .208 batting average against. He did get some batted ball luck, but he ranked in the 95th percentile in barrel rate and the 92nd percentile in ground ball rate according to baseball savant. Forcing the opposition into weakly hit ground balls sounds like a decent recipe for success to me.
The walk and stolen base issues Ottavino have had throughout his career remain an issue, but the negatives are outweighed by the positives. He had a 3.21 ERA in 66 appearances for the Mets this past season, and has been mostly reliable throughout his career. The Red Sox could use another late-game arm to pair with Kenley Jansen and Chris Martin, and Ottavino could be it at a relatively cheap cost.