MILWAUKEE — St. Louis Cardinals right-hander Adam Wainwright is coming back from the disabled list in time to start the home opener.

The Cardinals plan to activate Wainwright when the Arizona Diamondbacks visit Busch Stadium on Thursday, ending the veteran right-hander's season-opening stint on the 10-day DL for a strained left hamstring. He has been running and shagging fly balls with the team in Milwaukee, where the Cardinals were wrapping up a three-game series on Wednesday.

Manager Mike Matheny said the team decided that Wainwright was ready after giving him one last checkup Wednesday morning.

"I think they invented tests for me to try and pass to prove to them that I was ready," Wainwright said.

He'll take the start that was initially scheduled to go to Michael Wacha. The rest of the rotation will be pushed back a day to make room for Wainwright, whose 1,583 career strikeouts is second in Cardinals history only behind Hall of Famer Bob Gibson (3,117).

"I told them I would take whatever test they needed me to take. I didn't go into the manager's office and tell him 'I want tomorrow,'" Wainwright said. "I wanted to be respectful of Wacha and his position of potentially pitching tomorrow ... when he's also a very deserving candidate."

The Cardinals optioned Jack Flaherty to Triple-A Memphis to make room for Wainwright. Flaherty allowed one run on six hits in five innings against Milwaukee on Tuesday.