Former Seattle Mariners player we'll wish stayed: Erik Swanson
Oh man. The bullpen was so good last year. It was managed properly... well, almost all the time, and especially if you don't count the postseason. The Mariners decided to trade away some of their surplus, sending Swanson to Toronto alongside Macko for Teoscar Hernandez. Just like the one following this, I still like the move and think it was the right one, it's just been rough this year so far.
The moves that the Mariners made haven't really been working out, with Teo struggling a bit alongside Wong. Swanson was a legit stud last season for the Mariners, and it's hard not to think that they would have at least one more win if Swanson was around to shutdown a team late that otherwise turned into a blown save.
He's already been used in 6 games for the Blue Jays, giving up two runs across 5.1 innings while walking just one batter. That sure would be nice to have right now.