The reason: Stetter is a lefty specialist, in the truest sense of the word.
"They're not around baseball in general," Angels manager Mike Scioscia said. "That's why I know [general manager] Jerry [Dipoto] was excited to get Mitch when he had the opportunity."
Dipoto got Stetter on a Minor League contract in mid-November. The 32-year-old left-hander spent the entire 2012 season pitching in the Brewers system, with a 2.67 ERA and a 1.12 WHIP to go along with 11.9 strikeouts and 4.7 walks per nine innings.
From 2007-11, though, Stetter made 132 Major League appearances for the Brewers, posting a 4.08 ERA and holding opposing lefty hitters to a .194/.310/.335 slash line in 202 plate appearances.
Stetter only features a fastball-slider combination, and he isn't particularly overpowering. But he's a wiry 6-foot-5 and stands on the first-base side of the rubber and throws his pitches from an assortment of different angles, from three-quarters to something close to submarine.
"A lot of guys say it looks like the ball is being thrown from first base," said Stetter, who has faced righties and lefties in 2 2/3 innings this spring, giving up two runs on two hits to go along with three walks and three strikeouts.
"A lot of my pitching is deception."
The Angels already have two lefty relievers, in Sean Burnett and Scott Downs, but a guy who can come in for one or two lefty hitters could be beneficial considering who the Angels face to start the season.
The Reds are slated to have three lefty hitters in their starting lineup [Joey Votto, Shin-Soo Choo and Jay Bruce] and two lefty hitters off their bench [Jack Hannahan and Xavier Paul]. The Rangers have lefties David Murphy, A.J. Pierzynski, Mitch Moreland and Leonys Martin all slated to be in the starting lineup.
"Considering our bullpen, where it is, there's no doubt there's a possibility of a role for a guy like that," Scioscia said. "Especially with Kevin Jepsen still trying to finish things off, Ryan Madson not where he [needs to be], we'll have to have more of a situational look in our 'pen. We'll see where we are out of the gate."