McCreery walked out with them, and despite being "nervous as all get-out" delivered a stirring national anthem while a giant flag held by military troops waved in the outfield on a windy night at Busch Stadium.
"I'm looking forward to the game just as much as me singing," McCreery, 18, said before his performance. "This is huge. This is the biggest stage in baseball. As a little kid, I dreamed of playing here, but as I got older and wiser, and realized I'm not that good. But it's cool to be here. To be able to sing here and be able to see all the players, it's going to be intense."
McCreery and his new band visited the MLB.com studios in New York earlier this month on the day that his first album, "Clear as Day," was released, and on Thursday, those exclusive videos will be launched on MLB.com, along with his interview during the visit.
McCreery, who said he sings in the shower to prepare for a moment like this, has made it clear that the Cardinals and Rangers are great to watch but hardly his favorites. He is a fan of the Red Sox and Braves, the two teams that collapsed down the stretch and were bumped from postseason berths on that incredible final Wednesday of the regular season.
"I don't have a dog in the hunt this year," he said. "My teams are out. I'm just here to watch some baseball. I'm a baseball fan tonight.
"Aw, it was a painful night. Painful in Carolina, because I have two teams. The Braves are big there, too. It was just a bad baseball night for us in Carolina. But it's all good."
As he waited in the wings to sing the national anthem, McCreery was asked about all of his tweeting over his high school's big football game this Friday.
"Conference championship!" he said. "It's going to be a big deal back there."
But first, there was a big baseball deal.
For Game 2 on Thursday at Busch, pregame ceremonies will include an appearance by the Budweiser Clydesdales, the announcement of the Roberto Clemente Award presented by Chevrolet, a first pitch from Hall of Famer Lou Brock, and the national anthem by Trace Adkins.