The Iowa Cubs team bus had just left Principal Park when it stopped and turned around.

“We’re like ‘What’s going on?’” Jack Neely said.

The confusion was quickly answered — Neely was told to get off the bus — he was needed in Chicago because he was being called up to the major leagues.

“I was like, ‘All right, you got it,’” Neely said with a laugh. “[My teammates] were all super happy. They congratulated me. It’s a great group of guys down there.”

[WATCH: Jack Neely shares excitement over joining Cubs]

Neely was selected prior to Tuesday’s series opener against Detroit, with the team designating veteran Héctor Neris for assignment and clearing waivers.

The 24-year-old joined the Cubs last month in the Mark Leiter Jr. deal and has been impressive ever since. In 6.2 innings with the I-Cubs, Neely hasn’t allowed an earned run and has allowed just 4 hits and a walk. He’s struck out 13 of the 25 batters he’s faced.

“The numbers have been outstanding,” manager Craig Counsell said. “He’s striking out half the hitters he’s faced. That’s good. He earned a shot. And he earned his first time here. And we’ll get his feet wet here, and then see where it goes.”

That success has stemmed from a simple approach: sticking to what he does best. Neely isn’t loaded with a wide arsenal that can stymie hitters — instead, he relies on a simple fastball-slider mix to pick up outs.

“They just told me to go out there, do my thing, chuck the ball and let it eat,” Neely said. “I’m going in, I’m throwing strikes. I’m getting ahead of batters, and that’s all it really comes down to.”

The decision to part ways with Neris wasn’t easy — Counsell admitted he and president of baseball operations Jed Hoyer “had discussed [it] for a while”. But ultimately, the Cubs felt confident with where their bullpen was and wanted to get Neely — a pitcher they think can impact the team for years to come.

“We’re bringing a young player here who’s going to make his first big league appearance, who we think is talented and going to be a part of future teams — hopeful that he can be,” Counsell said. “We have lost experience, and that’s something that we didn’t replace, I guess.

“We’re hoping we can find another player here that can step up and make an impact and continue to provide some options for the rest of this year and moving forward.”