DECATUR — Chance the Rapper will play a concert in Grant Park in conjunction with the NFL’s season opener at Soldier Field, Bears chairman George McCaskey said Sunday.

The NFL already had announced a free fan festival at the park in conjunction with the team’s season opener Sept. 5 against the Packers at Soldier Field.

Public details about a Chance the Rapper concert remain scarce — McCaskey offered none when asked for specifics — though he joked that he was unsure if the rogue alligator that kinda-sorta shares the hip-hop star’s name would be in attendance.

“We’ll see if Chance the Snapper is going to show up and make a guest appearance,” McCaskey said.

Last week, the South Side rapper announced on “The Tonight Show” that his new album, “The Big Day,” would be released Friday.

The NFL is allowing the Bears to launch their season instead of the traditional Thursday opener featuring the Super Bowl champions because the franchise is beginning its 100th season. It seemed fitting to pit them against the Packers, whom they’ve played 198 times.

The NFL, not the Bears, is in charge of putting on the festival. McCaskey said the team will keep its attention on what’s between the lines, not in the park across the street.

“For us, the focus, of course, is entirely on the game,” McCaskey said. “That’s the most important part.”