The Mets' Rich Hill and the Cardinals' Adam Wainwright to lock up in over-40 duel

The main event at Citi Field on Monday is the Mets against the Cardinals, the opener of a series highly relevant to the National League playoff picture, though neither team will begin the day holding a spot.

But one of the subplots will be fun, too: Rich Hill against Adam Wainwright, the two oldest pitchers in the majors.

"AARP day," Hill said Sunday afternoon. "Get ready."

Hill will be 41 years and 186 days old, Wainwright 40 years and 14 days. Theirs is the first matchup of starting pitchers who are both at least 40 since the Mets’ Bartolo Colon and Blue Jays’ R.A. Dickey on June 18, 2015, according to the Elias Sports Bureau.

They combine for 33 major-league seasons, 741 games, 3,468 2/3 innings, 3,155 strikeouts and more than $200 million in career earnings.

The bulk of those totals belongs to Wainwright, who enters Monday seven strikeouts away from 2,000 for his career. He has had a far more straightforward career, debuting with the Cardinals in 2005 and staying ever since. Hill, conversely, has played for 13 organizations and dealt with even more injuries.

"Some guys have a pretty smooth career in the big leagues, success early on, which you can continue to parlay. You create that confidence, create the goodwill from the team and so on and so forth," Hill said. "For me, I didn’t exactly have the straightest line being in the big leagues."

Their paths nonetheless have crossed on several occasions — each, it turns out, with a lesson attached for Hill.

The only previous occasion they have pitched against each other: May 2, 2008, when Hill was with the Cubs.

"Probably not very good for me if it was 2008," he said.

He walked four of six batters . . .

"In the first inning. Yeah, I remember that."

. . . and was pulled from the game and sent to the minors. He didn’t return until the following year.

Informed by his experiences since, Hill realizes his error then: not saying anything about a back problem.

"You have to speak up when you have something that’s wrong and not try to fight through it or pitch through it," he said. "If you don’t play well here because of an ailment or because of an injury, they’re going to send you down. That was pretty stupid on my part."

During spring training 2010, Hill and Wainwright were teammates, with the former in St. Louis’ camp on a minor-league contract. He pitched in Triple-A for a couple of months but left and signed with the Red Sox, who eventually brought him to the majors.

The Cardinals wanted to turn Hill into a sinker/slider pitcher.

"It was very interesting," he said. "It’s a good lesson for a lot of people out there. You can’t mold everybody into being the same hitter or the same position player or the same pitcher. Sometimes that’s the easy way for some pitching coaches. But that is definitely not the way I would go about coaching or trying to teach guys how to be as successful as possible."

And now they will meet again during the indisputable twilight of their careers. Wainwright is a free agent this season, and he reportedly has talked with the Cardinals about signing for 2022, one last hurrah with fellow franchise icon Yadier Molina.

Hill isn’t ready to retire, either, he said. His preferences in finding a team for next year: something sort of close to his Boston-area home, and a team ready to win.

With those parameters, then, he is open to staying with the Mets.

"I’m obviously producing and pitching well and the ball is coming out of my hand great. I don’t really see any intentions of not playing," said Hill, who has a 3.82 ERA (3.71 with the Mets). "Here they’re going to be committed to winning next year, 100%. Because the fans want it, the city wants it, the team wants it, the guys in the locker room want it. And that’s something that I would love to be a part of."