The Tigers acquired Jose Iglesias to play short shortly before Peralta was suspended for 50 games for violating baseball's drug policy in August. When Peralta returned, the Tigers chose to keep Iglesias in the infield.
Asked how he plans to utilize Peralta as the series progresses, Tigers manager Jim Leyland said he'd take it game by game.
"I'm just going to use some statistical analysis, some gut feeling, a combination of those things," Leyland said. "We'll play it by ear. Basically what you do is, like every other manager, you put out the lineup that gives you the best chance to win that particular game."
Peralta said he'll take extra fly balls in Oakland to familiarize himself with the backdrop.
"I need to take some [practice]. I'd like to see how the field looks and everything," Peralta said. "That's important.
Peralta added that his mindset won't change, regardless of his role with the Tigers.
"Not starting the ALDS opener won't matter one way or the other," Peralta said. "Starting [Friday], starting whatever day, it's going to be the same. Same game. I'll try to do the best I can and whatever happens will happen.
"When I came back, they [just] said they wanted to see me practice in the outfield. Nothing about playoffs. Just come here and practice and be ready for whenever we need you. They know what I can do. From the beginning of the season, I did pretty good hitting No. 6 in the lineup. They might need me to pinch-hit. Whatever they want to use me for."
And he never doubted he'd be on the playoff roster, even after missing almost two months.
"They didn't need to say I'm on the team," Peralta said. "I'm here."
Jason Beck is a reporter for MLB.com. Read Beck's Blog and follow him on Twitter @beckjason. Paul Hagen is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.