CHICAGO -- When Adam Wainwright’s dramatically improved health lined up with another opening in the starting rotation, the Cardinals made the somewhat surprising decision to send their 41-year-old pitcher to the mound when they play the D-backs in Arizona on Monday.

Wainwright, who still needs two wins to become the third pitcher in Cardinals history to win 200 games with the club, received cortisone shots in his ailing right shoulder on July 5 and reported feeling much better in the last two weeks while throwing three bullpen sessions. While the team was originally scheduled to use the bullpen to cover a second start in six days, the Cards will instead turn to Wainwright to open the series at Chase Field.

“I’ve been trying to prove every day that I’m healthy, but naturally and not trying to force anything,” said Wainwright, who last threw a 50-pitch bullpen session at Wrigley Field on Friday. “The question for me [from the training staff] right away was, ‘What do you need from this before you can come back?’ I said, 'I’m not coming back if I feature the same stuff and I’m having the same problems and pains.' I will not come back for that because it’s not fair to the team.

“I said my only ask is that, when I am healthy, don’t slow-play me because I’m running out of time. They were gracious in that when I got healthy and passed some strength tests and the ball started coming out nicely, they said, ‘Hey, are you ready to pitch because we could use you in this spot?’ I said, ‘I’m ready. Let’s go!’”

At 3-4 with a 7.66 ERA, Wainwright has suffered through the worst season of his 18-year career with the Cardinals, missing time with groin and shoulder injuries and repeatedly getting hit hard. His best outing -- a 6 1/3-inning performance where he yielded seven hits and three earned runs in a win over the Mets on June 17 -- was followed by continued struggles. Poor showings against the Cubs (three innings, 11 hits and seven earned runs), Astros (1 2/3 innings, six hits and six earned runs) and Marlins (3 1/3 innings, seven hits and four earned runs) led to him being put on the injured list with a right shoulder strain -- pain he said he had been dealing with for weeks.

In hindsight, Wainwright said he should have gone on the IL weeks sooner to try and improve the health of his shoulder. When he returns on Monday, Wainwright feels hitters will see crisper stuff from him on the mound.

“It’s a dramatic difference because I can get that end-of-the-pitch life, but I guess we’ll have to wait and see what these hitters tell us,” Wainwright joked. “The catchers who I have pitched to and the pitching coaches have all told me this looks different, and this looks like last year, so that’s what we’re going for.”

Cardinals manager Oliver Marmol said starting Wainwright became necessary after Drew VerHagen was unable to continue pitching on Saturday following an 87-minute rain delay at Wrigley Field, when the club was forced to use Dakota Hudson over two innings of relief. Now, Wainwright gets another shot in the starting rotation.

“The whole time he didn’t want to throw live [bullpens] or go on a rehab assignment because he felt he didn’t miss that much time and he’s done three up-downs in the bullpen and he’s ready for 65 pitches,” said Marmol, who is hoping to get at least five innings out of Wainwright on Monday. “We were going to do the next live [bullpen session] and get him up to 80 [pitches], but our inability to get outs out of the bullpen on Saturday … put us in a little bit of a pinch for innings on Monday. So, that’s why we’re here.

“[Wainwright] feels good and this is the best he’s felt all year, so let’s see it."