JUPITER, Fla. -- Cardinals manager Mike Shildt refused to let the thought cross his mind this offseason.

Could Adam Wainwright really sign with a different team?

“Honestly, I couldn't get in my head that Waino wouldn’t come back,” Shildt said Tuesday. “... I just didn't see Waino in another uniform and didn't want to put mental energy into something I didn’t think was going to happen.”

Energy not exerted is energy saved.

That Wainwright re-signed for his 16th Cardinals season at the end of January was of little surprise. Though he had offers out there -- two, he said, of greater value with different teams -- he said he had zero doubt he wanted to return as a Cardinal, if the logistics worked out.

So call Tuesday, Wainwright’s spring debut, not an alleviation of worry but more a culmination of excitement. The righty needed just 20 pitches for his planned two innings in a 0-0 seven-inning tie with the Marlins, picking up right where he left off after the 2020 season. Uncle Charlie flashed his trademark curve down into the 60 mph zone, notching a strikeout in two perfect innings.

“It's going to be hard to sit on a 68 mph curveball,” Wainwright said. “KK [Kwang Hyun Kim] came over and goes ‘68, not bad. Tomorrow I'm going to try to beat it.’”

Keeping hitters off-balance is part of the natural maturation process Wainwright continues to go through as he looks to remain a rotation stalwart with his 40th birthday coming in August. In a moment of reflection on Tuesday, he called 2014 the best season of his career -- from both a throwing and pitching perspective -- and after a tough run with a 4.58 ERA from ‘16-19, he flipped that to a 3.15 mark last season.

“I'm certainly a better pitcher now than I was a few years ago,” he said. “I’m getting back into a lot of the things that I used to do really well.”

Part of that is what made the calls for Wainwright to return this season incredibly loud -- louder than he’s heard in past years.

“Guys like [Daniel Ponce de Leon], guys like [Austin] Gomber, [Jake Woodford], reached out to me and said, 'Dude, you can't retire,’” Wainwright recalled. “I appreciate that so much, for the guys who are really on the doorstep of breaking in and making a name for themselves. They could be selfish guys, but they're not.”

The Cardinals will look to Wainwright in two ways this season. First, as the rock of the rotation that he was in 2020. That doesn’t necessarily mean the ace, but the steadying force -- the same one that carried the club to a win in its return to action after the COVID-19 outbreak put a pause on the season.

And the second, as it’s been for many years now, is Wainwright's leadership. During the pause last year, he was the team's outspoken force around the clubhouse though the ups and downs of the season.

“Clearly, there were a lot of factors to our ability to overcome unprecedented obstacles last year and still get to an area that we expect to get to, and that's the playoffs,” Shildt said. “And Adam Wainwright was a huge factor in that. …

“I can't even articulate all what he did, because I probably don't know all of it, quite candidly,” Shildt added, alluding to an impact that reached all corners of the clubhouse.

That’s a factor in what made it such a natural choice in the end for Wainwright to return to St. Louis. He and Yadier Molina are synonymous with 21st century Cardinals baseball. The two are taking their careers season by season -- both re-signed on one-year commitments -- with the chance to climb through the ranks of starter-catcher batteries in 2021.

That wouldn’t be possible if Wainwright signed elsewhere -- if he decided he wanted to endear himself to a new fanbase, new teammates, new digs after 15 years of the same.

Shildt never let the thought cross his mind. That doesn’t mean Wainwright didn’t.

“I'll be honest, part of that seemed kind of interesting to me,” Wainwright said. “It seemed kind of a new adventure.

“But I'm liking the new adventure we're having inside the same clubhouse.”