ST. LOUIS — Well before he ever got to Busch Stadium and pitched the game of his young professional life for the Cardinals on Wednesday, Michael McGreevy put himself through the ringer emotionally with a wild series of assumptions as he answered a phone call from Triple-A Memphis manager Ben Johnson.

Mature well beyond his 24 years of age and mentally strong enough to dig himself out of a slow start to the season, McGreevy said his mind played tricks on him and he feared the worst when the Redbirds skipper phoned him just hours before the Trade Deadline.

“I get a call from Ben Johnson and I’m like, ‘Well, I just got traded!’” recounted McGreevy, willingly mocking his wild train of thought at the time. “Then, when he said, ‘Mac, I’ve got good news,’ I was like, ‘Well, he knows that I’m from Southern California, so maybe it’s a team out there.’

“[Johnson] was like, ‘No, even better … You’re going to the bigs!’ That was a lot better [news].”

Remarkably, things got even better for the fresh-faced right-hander on Wednesday as he held the defending champion Rangers scoreless for 5 1/3 innings before putting the finishing touches on a one-run outing on five hits and one walk over seven innings as the Cardinals thumped Texas, 10-1, at Busch Stadium.

“Oh man, that was awesome to watch, and probably the most impressive thing was how much he was in control,” Cardinals manager Oliver Marmol said of McGreevy, who struck out three. “You wouldn’t have thought it was his first time out there on a big league field. He didn’t make the moment any bigger than it was and he was calm throughout. He did what he does — he kept [Rangers] guys on the ground. Overall, that was fun watching him and keep sending him back out there every inning.”

It didn’t hurt that the Cardinals got three more hits and two more RBIs from veteran slugger Tommy Pham, who hit an opposite-field grand slam to begin his second stint with St. Louis. On Wednesday, Pham singled in the second inning, doubled in two runs in the fifth and added a third hit in the seventh. Since joining a Cardinals offense that has pounded out 23 hits and scored 18 runs over the past two games, Pham is 4-for-6 with three runs scored and six RBIs.

“Any time your team is trying to get into the postseason and your front office acquires talent at the Deadline, it gives your team a jolt,” said Pham, who was acquired by St. Louis along with pitchers Erick Fedde and Shawn Armstrong. “When you feel like you could get to the postseason, but your front office does nothing, it’s telling you, ‘They don’t think we can do anything, they don’t think we can win, we didn’t get any help.’ In this situation, it lets you know the front office has our back and it kind of lights up a clubhouse.”

Pitching in front of dad and mom, Steve and Wendy McGreevy, and grandmothers Judy and Nancy — all of whom scurried to catch flights from Southern California to St. Louis on Tuesday night and Wednesday morning — McGreevy retired 11 straight after yielding a first-inning double to Marcus Semien. The 6-foot-4 righty, who was ranked as the No. 15 prospect in the organization by MLB Pipeline, leaned on his heavy sinker to get 12 ground ball outs. He and catcher Pedro Pagés also attacked a lot of left-handed hitters with changeups and curveballs to keep them guessing and off stride.

“From the beginning of the game, I asked him if he was nervous, and he said no. But I thought he was lying,” joked Pagés, who had a familiarity with McGreevy from their time together in Triple-A. “But he went out there and competed and stayed calm and collected.”

The owner of a 4.45 ERA at Triple-A in 2024, McGreevy never felt further from the big leagues than on May 29 — a start where he posted a 6.02 ERA in April and May. He surrendered nine runs (seven earned) in a loss to Nashville, but it awoke something inside of him. Since then, McGreevy posted a 2.94 ERA in his past nine Triple-A starts. On Wednesday, he backed up that run with a debut he won’t forget.

“[Kyle Gibson] said that I was lying [about not being nervous], but this is what I’ve been dreaming about and training for since I was little,” he said. “You don’t train for college baseball or the Minor Leagues, you train to be here. When I got here, it was cool, but I told myself, ‘You’ve got a job to do.’ That helped calm whatever nerves I may have had.”