The Detroit portion of Peralta's career looked like it might be over when he was suspended 50 games on Aug. 5 following Major League Baseball's investigation of the Biogenesis of America anti-aging clinic. Despite the long layoff, he's been able to contribute in the postseason, saving the Tigers with a big home run in the division series and adding needed power to the lineup.
Peralta's return has raised the usual questions about doping in baseball and whether his punishment was harsh enough. The Tigers are happy to have him back, whether he's at shortstop or in the outfield.
''I think I have a new life, a new opportunity,'' Peralta said. ''It's important, how Detroit gave me the opportunity to come back here. I appreciate everything.''
Peralta was in the middle of a fine season when his suspension began. The Tigers had anticipated his absence, acquiring smooth-fielding shortstop Jose Iglesias from Boston shortly before the suspension.
Eligible for free agency after the World Series, Peralta returned for a three-game series at the Miami Marlins as Detroit closed the regular season. That didn't leave him much time to prepare for any playoff games.
He had gone to the Dominican Republic to try to stay in shape during the suspension, then spent some time in the instructional league.
As they closed in on their third straight AL Central title, the Tigers said they'd give Peralta a chance to earn a spot on the postseason roster. Because Iglesias had impressed as the new shortstop, Detroit said Peralta would have to learn to play left field.
''It was a cram course,'' said manager Jim Leyland, who has used Peralta at shortstop and left field during these playoffs. ''I don't know how this is happening. I'm not sure he's totally comfortable in left field yet. I'd be lying if I said I was totally comfortable with him in left field yet.''
But with Miguel Cabrera hobbled and Prince Fielder struggling, the Tigers have needed offense in this postseason, and Peralta has provided it. In Game 4 of the AL division series against Oakland, Detroit trailed 3-0 and was facing elimination when Peralta connected for a three-run homer in the fifth inning - perhaps the biggest swing of the playoffs for the Tigers so far.
Detroit went on to win that series in five games. Now the Tigers trail the AL championship series 3-2, with Game 6 at Boston set for Saturday.
Peralta's RBI single brought home the only run of Game 1 against the Red Sox. He's hitting .367 this postseason, with four doubles to go along with that big home run.
''Instructional league I think helped,'' Peralta said. ''They really have good pitching over there. They throw hard, and they throw everywhere.''
Peralta has been the target of derisive chants from opposing fans - par for the course for a high-profile player implicated in a drug investigation. The San Francisco Giants did not bring back Melky Cabrera last year after his suspension. They ended up winning the World Series without him.
The Tigers chose a different course, not feeling any obligation to add more punitive measures once Peralta had served his ban.
''I think the majority of the club felt that he handled it as well as he possibly could. He made a mistake, he admitted he made a mistake, he apologized, he worked hard to get back,'' general manager Dave Dombrowski said. ''He paid his due, he paid his penalty, and who am I or who are we to really enforce more?''
Now Peralta is doing his best to make up for lost time.
''I try to be positive and try to help our team,'' he said. ''And try to win games every day.''