In two seasons with the Seattle Mariners, Perez revitalized his career in moving from the starting rotation to the bullpen. Those two years in the Emerald City produced a 4-6 record, 3.16 ERA, 1.367 WHIP and a SO/9 of 10.7.
Perez didn’t experience the success last season as he did in 2012. You could argue that in 2012 he was one of baseball’s better lefty relievers. He mustered a 0.9 bWAR. Not a big deal until you realize he did that in only 29.2 innings. He was far more effective against right-handed batters limiting them to a .204 BAA. That number against LHB was an almost gaudy .281.
Last season, those splits saw the gap decrease. In facing RHB, the BAA rose to .256, an increase of over 50 points. He was more effective against lefties, as you would normally expect for a lefty out of the pen, with a BAA of .238. He did manage a career-high SO/9 of 12.6.
In 2004, Perez was part of a Pittsburgh Pirates rotation that included Josh Fogg, Kip Wells, Ryan Vogelsong, Sean Burnett, and Kris Benson. The Buccos finished 72-89, but Perez was the star of the staff. Only he (143) and Benson (102) finished with a ERA+ over 100.
The bugaboo with Perez has been his excessive walk rate. For his career, his BB/9 is 5.0. He has somewhat curtailed the walks since moving to the bullpen, posting a 3.9 with Seattle (3.0 in 2012, 4.4 in 2013).
With the deal, Perez could become Kirk Gibson‘s #1 lefty option out of the bullpen. The Snakes do have lefties Eury De La Rosa and Joe Thatcher on the 40-man. Ryan Rowland-Smith is in camp as a non-roster invitee.