Sean Doolittle Should be the Mariners’ Primary Lefty Reliever

Over the course of this season, the Seattle Mariners have primarily used Anthony Misiewicz as their left-handed specialist out of the bullpen. Left-handed relievers are important for neutralizing powerful left-handed hitters in opposing lineups, but Misiewicz hasn’t been able to effectively fill that role this year, as left-handed hitters have still been able to hit .253 against him; recent acquisition Sean Doolittle, though, has performed better and should take his spot in the ‘pen.

Doolittle, a 35-year-old left-hander claimed off of waivers from the Reds mid-season, has limited opposing left-handed hitters to a .227 batting average, while striking out 10 batters through 10 innings pitched since joining the Mariners. Doolittle is a better strikeout pitcher than Misiewicz, and strikeouts are an important part of a bullpen pitchers game, as they often come into the game with runners on base and little margin for error.

The Mariners’ Sean Doolittle and Anthony Misiewicz are similar pitchers, but recent performance trends favor Doolittle over Misiewicz.

Mariners fans have been frustrated by Misiewicz’s performance over the last couple of weeks; since September 12th, he’s pitched three total innings while giving up five runs on nine hits, including a dud of an outing against the lowly Arizona Diamondbacks in which he gave up three runs without recording an out. Doolittle, on the other hand, has pitched five innings since September 11th, and has only given up one run and one hit.

In a playoff race, especially one in which a major calling card of the contending team has been its bullpen, there is little allowance for mistakes by relievers. The Mariners have found success while riding hot hands down the stretch this season (such as bumping Jarred Kelenic higher up in the order during his recent hot streak, despite posting a season batting average in the .170’s), and they would be wise to take a similar approach with Sean Doolittle in their bullpen pecking order.