Long known for a combination of excellent stuff and iffy (or worse) location, Perez has at least temporarily harnessed his control as a member of the Seattle Mariners' bullpen. He's posted a 1.71 ERA in 21 innings (24 appearances), with 22 strikeouts and seven walks. It's that last number that is most critical.
Even at his best, as he was in the 2004 and '07 seasons when he was successful as a starter, Perez walked far too many batters. If he has truly arrested that trend -- and it's admittedly too early to declare that without reservation -- he could have quite a second career.
Perez explained that it's as much a mental matter as anything physical. He believes the move to the bullpen has sharpened his focus.
"You have to make sure that you throw strikes [in relief]," Perez said. "You have to know the batter, if he swings early or doesn't swing early. It's way different from being a starter. As a starter, you have more time to play with other pitches and all that other stuff. As a reliever, you have to throw strikes."
Perez pitched 10 games in relief for the Mets in 2010 -- his last season in New York -- but it didn't really take. Before that, the last time he spent any significant time in the 'pen was at the beginning of his professional career, pitching short-season ball in the Padres' organization.
This time around, it was about his only choice. Perez made 16 appearances (15 starts) for the Nationals' Double-A Harrisburg affiliate last year, and he was effective. But he never got a callup, and he believes that actually turned out in his favor. Perez shut it down for a month after the Minor League season ended in early September, started pitching early in the winter-ball season in Mexico, and came to Mariners camp in strong shape.
After 22 appearances at Triple-A Tacoma, Perez got the call to Seattle, and it's been one of the season's best success stories.
"I do feel like this is the right role for him," said Mariners manager Eric Wedge. "I told him in Spring Training, 'This should be the start of your second career.' He did what he needed to do at Triple-A, and he's done what he needs to do up here."
Then there's the matter of health, which is often a good place to start when wondering about fluctuations in players' performance. Perez battled knee troubles throughout 2009 and '10. He underwent surgery on the joint late in '09, but now believes he came back too quickly from the surgery in '10.
It's not an uncommon thing to happen, as players want to get back to doing what they do. But it's rarely the right move, and it's entirely possible that Perez's 2010 performance was compromised by the condition.
"The last few years were really tough for me, because I was not healthy enough," Perez said. "I was not able to be consistent. I wasn't as strong. Right now I feel good, feel strong. My legs are very strong. I tried to get better and recover and get healthy."
Perez said it's been four years since he was as healthy and strong as he is now. That's also the last time he was a league-average pitcher, posting a 4.22 ERA in 34 starts for the Mets in '08.
He's more than that now, and it's been quite a find for the Mariners and quite a revival for Perez. Now he just needs to keep it up.
"I feel good right now," Perez said. "They've given me a lot of opportunities here, and I'm really comfortable here. I'm pretty happy with what they've done for me. I just want to finish the year strong and see what happens next year."
Matthew Leach is a writer for MLB.com. Read his blog, Obviously, You're Not a Golfer and follow him on Twitter at @MatthewHLeach. This story was not subject to the approval of Major League Baseball or its clubs.