"I think with Ollie, it's power, it's different arm slots," D-backs general manager Kevin Towers said when asked about what prompted the club to sign Perez. "It's a guy that controls the running game. It's a guy who fields his position well. It's a guy who's not just a situational left-hander. He can maybe even throw two innings."
The D-backs thought they had solved their need for a lefty specialist last season when they acquired Joe Thatcher from the Padres in the Ian Kennedy trade.
But Thatcher struggled with a 6.75 ERA after coming over to the D-backs, and as Perez went unsigned, Towers, who as the GM in San Diego signed Perez at the age of 17, decided to make a move.
Thatcher could still open the year with the D-backs in addition to Perez, but it seems unlikely.
"In a perfect world, it'd be nice to have multiple lefties in our 'pen," Towers said. "Don't know exactly how that's going to play out. Joe struggled with us last year. This spring, he's been OK. I think Ollie was somebody that we felt, if the deal made sense, it was going to be somebody that we think could significantly upgrade our bullpen."
To make room on the 40-man roster for Perez, the team outrighted lefty Santos Rodriguez to Triple-A Reno.
After struggling with the Mets as a starter in 2009 and '10, Perez went to the Nationals organization. He spent the 2011 season with Double-A Harrisburg working with pitching coach Spin Williams, who had been his pitching coach when he was with the Pirates early in his career.
"He told me after the season ended, he said, 'You always had good success against lefties and righties, the fastest way to get back to the big leagues is as a reliever,'" Perez said. "You just have to go to winter ball and get used to being a reliever. Then when you go to Spring Training, you can be available to show everybody how good you can be in the bullpen."
That's exactly what Perez did.
In 2012 and '13 with the Mariners, he compiled ERAs of 2.12 and 3.74.
"It's kind of more fun," Perez said of being a reliever. "As a starter, you have plenty of time to think about the game. But as a reliever, you're normally going into key situations, and your team is going to win or your team is going to lose. For me, it's very exciting. When I go to the mound, I know that I could personally decide the game."
Because Perez is a reliever and pitched recently in winter ball, he shouldn't have trouble being ready to pitch out of the bullpen when the team begins its regular season March 22 against the Dodgers in Australia.
As it stands, Addison Reed, J.J. Putz, Brad Ziegler, David Hernandez, Josh Collmenter, Randall Delgado and Perez seem to be locks for the bullpen. With the different roster rules for the two-game Australian series with the Dodgers, the D-backs could carry a couple of extra relievers, one of which would likely be Will Harris.
Harris pitched well for the D-backs last year and has looked good this spring, but with Delgado out of Minor League options, it appears that Harris could end up starting the year in the Minors.
"Again, that's a good problem to have," D-backs manager Kirk Gibson said. "You want to have good, viable options, you want to have guys competing for jobs, you want everyone throwing well. We know we're going to need the depth. We've got a good pool of guys that are throwing the ball well."