"[I was] an inch off here, 2 inches off here, which causes the very end of the pitch to be a much different result than you want it to be," Wainwright said. "There were some things I was doing wrong that were inexcusable. There was some crazy stuff going on with my delivery that was a first for me."
Wainwright tinkered with the mechanics of his delivery throughout Spring Training, though that's not unusual. What was is the fact that he couldn't get in sync for his first regular-season appearance. In the previous two years, Wainwright shut out his opponent on Opening Day.
He acknowledged the issues could have been a carryover of some bad habits he fell into when returning late last season or simply the result of not having pitched for most of 2015.
It wasn't until Wainwright stood in front of a mirror this week that his delivery began to fall back into place.
"The great thing was the first two or three flaws I fixed, I get out over my leg for the first time throwing a ball and I felt my legs for the first time," Wainwright said. "I felt a hamstring stretch. Instead of swinging my leg, I felt my hip flexor actually pulling my leg up. I'm thinking, 'I haven't felt this all spring. I haven't been properly using my lower half this entire Spring Training.'"
He took that work into his midweek bullpen session, which Wainwright said went well.
His outing Sunday will not only close the Cardinals' first road trip, but it will also mark the final regular-season game the team will play at Turner Field. That has a bit of sentimental meaning for Wainwright, a Georgia native who was selected by the Braves in the 2000 Draft.
He first came to Turner Field during the 1996 Atlanta Olympics and joked that he would drive past the ballpark as a high schooler telling his then-girlfriend he'd pitch there one day. Wainwright finally did in 2006, when, as a rookie reliever for the Cardinals, he threw two scoreless innings on July 4.
"It's pretty special when you're facing the guys you grew up adoring," Wainwright said. "And seeing [John] Smoltz and [Tom] Glavine, those guys on the other side? That will always be in my brain."
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, follow her on Twitter @LangoschMLB, like her Facebook page Jenifer Langosch for Cardinals.com and listen to her podcast. This story was not subject to the approval of Major League Baseball or its clubs.