ST. LOUIS -- Openly bothered for weeks as to why he struggled during the stretch run of the season, Cardinals pitcher Adam Wainwright thinks he has finally found the root of his problems -- albeit, too late for it to help St. Louis in the postseason.

A historically strong finisher to the regular season with 40 career wins in September and October, Wainwright wobbled badly late this season with subpar outings in five of his last six outings. That resulted in Wainwright not pitching in the Wild Card Series -- a 2-0 series sweep by the sixth-seeded Phillies that eliminated the Cardinals and retiring stars Albert Pujols and Yadier Molina.

In a series of detailed posts shared on Twitter on Wednesday, Wainwright pointed back to the hard-hit ball off Austin Riley’s bat in the game between the Cardinals and Braves on Aug. 28 at Busch Stadium. That ball, which left Riley’s bat at 103.5 mph, ricocheted off Wainwright’s left knee, but he still scrambled to get the ball and threw to first for the out.

Wainwright, 41 and in his 17th MLB season, stayed in that game and pitched well enough for the Cardinals to rally and win. However, he feels the lingering pain from the comebacker affected his stride length and ultimately had an adverse effect on the pitches he’s used throughout his career to rack up five top-five finishes in Cy Young Award voting.

“Without knowing it, after that [Aug. 28] game my stride length got shorter by almost a foot,” the 6-foot-7 Wainwright posted on Twitter. “Timing was thrown [off]. That had never been a problem for me in the past. My stride length has always been very consistent. Because my timing was so badly off, my front arm started to try and create power by pulling. And when that happens, you just pull yourself off target.”

Wainwright, who has yet to disclose whether he plans to pitch in 2023, went 11-12 with a 3.71 ERA in 32 starts -- the first losing season of his career in which he made at least 20 starts. He claimed he “ruined” a good season with just two wins and a 7.22 ERA over his final six starts. That poor closing stretch, one that he repeatedly blamed on a “dead arm” condition left him five wins short of 200 for his career and he finished 8 1/3 innings pitched shy of his preseason goal of 200.

Wainwright blames himself -- both for letting his delivery slip out of whack and for letting his team down with so much at stake during the playoffs.

“Let me say this, it's my fault,” Wainwright posted on Twitter. “I didn't stay diligent enough with my film work to catch it immediately. It wasn't something I had struggled with before. The zip and crispness to my stuff returned as soon as we locked in on the problem. What I was attributing to dead arm was an awful delivery.

“The end of the season should have been way different for me, and who knows what happens if I'm sharp down the stretch,” Wainwright continued. “I feel terrible about it. Y'all deserved better. My team deserved better. I owed an explanation ... so there you go. Go Cardinals.”

Following Saturday’s elimination -- one that the veteran pitcher lamented because it meant the end for Pujols and Molina -- Wainwright said he should soon have a decision as to whether he will join his teammates in retirement or pitch in 2023. President of baseball operations John Mozeliak and manager Oliver Marmol have both repeatedly expressed their desire to have Wainwright pitch again next season if he so desires.

Wainwright made it clear that he did not like being left out of the postseason pitching rotation -- a result of those late-season struggles that came about, he said, because of his delivery issues.

“We’ll see what happens. We should know pretty soon if something happens,” Wainwright said Saturday, referring to him potentially being offered a one-year contract for 2023 by the Cardinals. “If not, it’s been a good run, and thank you, St. Louis.

“I’ll tell you this: I do not like not pitching a playoff series,” he added. “So, you can take that in one of two ways -- you can take that as it’s been a good run, or you can take it as motivation to never let that happen again.”