Drew Smyly threw a warm-up pitch and determined that he could not continue in the doubleheader nightcap Monday.

That meant Anderson Espinoza was the next man up, trotting out from the Cubs bullpen for his MLB debut — warming up on Wrigley Field in a unique situation as an injury replacement.

It wasn’t an ideal way for Espinoza to make his debut. But then again, nothing about Espinoza’s career has been ideal to this point.

The 24-year-old right-hander was one of the best pitching prospects in the game earlier in his career, topping out at the No. 19-ranked prospect by Baseball America entering the 2016 season with the Boston Red Sox.

But he missed four full seasons (2017-20) due to a pair of Tommy John surgeries and then the pandemic.

So Monday’s appearance was a long time coming for Espinoza.

“Really at a loss for words,” he said through team translator Will Nadal. “I’m just thankful to God, to the organization for giving me this opportunity.

“I never lost faith. I always knew the talent that I had. I kept on working and thankfully this day came.”

Espinoza came up big for the Cubs Monday, salvaging a weary pitching staff that has been hammered by injuries of late. He threw 4 innings, striking out 6 and allowing only 2 runs to keep the Cubs within striking distance against the Brewers.

“Handled it really well,” David Ross said. “I thought he settled in as the game went on. Really commanded the strike zone. A couple misfires there. Really big outing for us to keep us in that ballgame. That was huge.”

The Cubs acquired Espinoza from the Padres at the trade deadline last season in exchange for outfielder Jake Marisnick.

He was already on the 40-man roster so when the Cubs needed a “27th man” for Monday’s doubleheader, Espinoza was a simple choice as the organization currently faces a serious roster crunch.

He hasn’t quite found his footing yet at Double-A Tennessee this season (0-4, 7.31 ERA in 8 starts) but Espinoza is grateful the Cubs took a chance on him.

“Once I was traded over to the Cubs organization, I feel like they really let me be myself,” he said. “I’ve acquired a slider, which is something I didn’t have before. I used to throw a fastball, changeup, curveball. But now with that new pitch, I’ve been doing pretty well.

“Thanks to God, I’ve gotten the opportunity to go out there and continue to prove it.”