7: Erik Swanson, Toronto Blue Jays
As Blue Jays fans are well aware, the team gave up a lot to acquire Erik Swanson this offseason. He and a low-level minor league pitcher were the return from the Seattle Mariners for two-time Sliver Slugger and longest-tenured Blue Jay, Teoscar Hernández. The idea of trading a star outfielder for a reliever certainly wasn't ideal at first, but as the dust has begun to settle on the deal, more and more people are starting to see Swanson for who he is; a really solid reliever.
2022 was a breakout season for Swanson, who had a 1.68 ERA in 53.2 innings pitched, and his 7.0 strikeouts per walk was second among AL relievers with at least 50 innings pitched, behind only Emmanuel Clase. He's got a solid fastball as his primary, usually sitting in the mid-90s, but his best pitch by far is his splitter. While it might not be on the level of Kevin Gausman's, it's still an outstanding pitch. Against lefties in particular, this pitch is almost unhittable, with all batters only having a .129 average against it last season. Statcast absolutely loves him, as he sits in the top six percent of the league or higher for average exit velocity, xSLUG, wOBA, xwOBA, hard hit rate, strikeout rate, and xERA. The main argument you could levy against him is that he's only had one truly great season, but his peripherals are more than good enough to prove it wasn't just a fluke.
Toronto's closer role is already filled by someone near the top of this list, so Swanson will likely just be in a setup role, but he's got a shot to be one of the best in the league. The Blue Jays obviously have faith in him, considering what they gave up to acquire him, and he's entering his age 29 season which is where many relievers hit their peak. Seven feels like a fair ranking for him now, but don't be surprised if he exceeds expectations in 2023.