ST. LOUIS -- Daniel Ponce de Leon understood there was little need to unpack, not this time around. His assignment was simple: fill in for an injured Michael Wacha, contain a mighty Brewers offense and do it all knowing that regardless of the result, he’d likely not stick around for another day.

The right-hander can leave, however, knowing the impression will outlast his stay.

Ponce de Leon, who expected to be optioned back to the Minors after the Cardinals’ 4-3 victory on Tuesday, will return to Triple-A Memphis having convinced the Cardinals that he has course corrected after a rocky spring. In holding the Brewers to one run over five innings, he also asserted a readiness to contribute at the big league level.

“There was like a whole different person than I was in Spring Training,” Ponce de Leon said afterward. “I’m very happy to come up here and perform.”

His presence on the depth chart shouldn’t be understated, either, particularly on a day when the Cardinals made official their plans to prepare Carlos Martínez to pitch in relief. With Martinez unable to shoulder a starter’s load and Alex Reyes still at least a month away from possibly being ready to do the same, the Cardinals don’t have a plethora of ready and experienced options.

Austin Gomber is one. Ponce de Leon, the other.

“Step in, step up. It’s important,” manager Mike Shildt said. “We’ve talked about this with Gomber and Ponce. They’re big league players, big league pitchers, who happen to be in Triple-A. That’s what good organizations, good teams, have. They have depth. We don’t like to rely on it, but we know it’s there and we trust it.”

“Me and Gomber both believe what Shildt says,” Ponce de Leon added. “We believe we’re big league pitchers. We just didn’t perform in Spring Training. The other guys who are here deserve to be here. We just have to wait for our turn now.”

Ponce de Leon’s came first, mostly because it would have been his night to pitch for the Redbirds. But he arrived riding a wave of confidence that had been building since a conversation with reliever Chris Beck last week. Still searching for feel of his fastball, Ponce de Leon started dissecting his arm path with his teammate.

Ponce de Leon then tweaked it ahead of his last Minor League start, and, voilà, the pitch that he couldn’t command all spring was a weapon once again.

“When you don’t have a fastball, you’re kind of naked out there,” Ponce de Leon said. “Once the fastball is there, I’m back to myself.”

He established the pitch -- particularly up and inside -- on Tuesday, throwing it 61 times in his 90-pitch outing. It helped him set up his improving curveball and compensate for never truly finding a rhythm with his changeup or cutter.

“I think he did a pretty good job of locating at the top of the zone,” said Brewers third baseman Travis Shaw, who struck out twice against Ponce de Leon before taking John Gant and Jordan Hicks deep later in the game. “Even his balls were just up, so they were tempting enough for guys to swing at. And his four-seam does have life, so it's a tough pitch to cover when he's at the top of the zone like that.”

It was a far different look than the one Ponce de Leon had shown the last time he pitched in front of Shildt. That was on March 20, a day in which the right-hander gave up five runs while being chased from the start in the fourth inning.

The outing not only closed his participation in the fifth-starter competition, but it concluded a stay in Major League camp that had been far from flattering. Ponce de Leon was sent out having walked 12 while allowing 15 runs in 15 1/3 innings.

He issued another three free passes on Tuesday, though he worked around them with relative ease. A solo homer from Orlando Arcia squandered Ponce de Leon’s early one-run lead, but it was also the only run he surrendered. The Cardinals later countered with a tie-breaking homer by Paul DeJong in a two-run eighth to assure the club its first series win against the Brewers.

Despite still being in search of his first Major League win, Ponce de Leon lowered his ERA in 12 appearances (five starts) with the Cardinals to 2.61.

“The reason we were so comfortable and confident with the call to Ponce was his body of work last year,” Shildt said. "We know how he’s capable of pitching. I loved his body language. I loved his aggression. And I loved his ability to execute his pitches.”