Leyland said Monday that Peralta will leave for the instructional league Wednesday. He is eligible to return Sept. 27 from his 50-game suspension that resulted from baseball's investigation into Biogenesis of America, a Florida anti-aging clinic accused of distributing banned performance-enhancing drugs.
Peralta was Detroit's starting shortstop, but the Tigers acquired Jose Iglesias from Boston just before Peralta was suspended. General manager Dave Dombrowski already has said if Peralta returns, it won't be as the team's everyday shortstop.
Leyland said Peralta will work in the outfield in the instructional league, trying to show he can help the Tigers after a long layoff.
"I don't know if you want to call it a longshot, a 50-50, I have no idea," Leyland said. "Dave will make a decision at some point. He'll go down there, and we'll be getting reports from down there, from the guys that are down there, on how he looks. How he looks in left field, how he's swinging the bat."
Leyland didn't want to speculate on whether Peralta would be part of the roster if the Tigers reach the postseason. Detroit led the AL Central by five games heading into Monday night's matchup with Seattle.
"I assume -- I don't know this to be a fact, but I assume -- that he'll probably join us in Miami," Leyland said.
The Tigers play their final three games of the regular season against the Marlins from Sept. 27-29.
Peralta, who will be a free agent after the season, has never played the outfield in the major leagues. He's only played shortstop, third base and first base, and the latter two positions are occupied by sluggers Miguel Cabrera and Prince Fielder.
Peralta was having a fine season before he was suspended, hitting .305 with 11 home runs.
"I'm sure it'll be a big deal for Jhonny to get back out there. Like I say, we'll just have to wait and see what happens," Leyland said. "He's going down there basically to work out, see some live pitching, get some instruction on playing left field, and play left field in the games down there."