PITTSBURGH -- Several hours before the Cardinals' series opener on Monday, Adam Wainwright took the PNC Park mound to throw his third simulated inning of the past week. He may be back on that mound, too, before the team departs Pittsburgh on Wednesday night -- this time pitching in a meaningful setting for the first time since April.

If Wainwright recovers well from this final test, he's expected to be activated from the disabled list and available out of the Cardinals' bullpen on Wednesday. Coming back from April surgery on his Achilles, his return would come with just four regular-season games remaining, but in time for him to pitch in at least a pair of them to give the Cardinals a glimpse of what he could offer in the postseason.

"My leg feels normal out there," Wainwright said after Monday's exercise. "I really can't ask for a better rehab than I've had. Things went well. I've passed all my tests."

• Shop for Cardinals' postseason gear

Wainwright estimated he threw about 20-25 pitches to hitters on Monday afternoon. The session wasn't so much to give Wainwright's arm another test but to assess how his legs responded. Thus far, he has had no issues coming off the mound to field his position or cover first base.

"He responded really well," said manager Mike Matheny. "That's something we can check off, and we'll see how he responds tomorrow. The medical team will do their evaluation, and if all goes well, we could see him available in the bullpen soon."

The Cardinals haven't scripted how they would like to use Wainwright out of the 'pen as the regular-season winds down. The most important thing is to get Wainwright game exposure, but with the Cardinals still playing meaningful games, finding the right place could be tricky.

"I think when you're looking at where he is now, you have to be careful to not put him in a place where he could get overexposed or too stressed," general manager John Mozeliak said. "It's not hard to imagine that when we get into October, if we were to advance, seeing him in a more high-leverage situation."

Wainwright, who hasn't pitched out of the bullpen since 2006, is ready for anything. And asked after his session on Monday how he felt with his command, he grinned: "I saved a little extra for whenever that first game will be."