**Related Video Above: Browns Practice Friday before before Steelers MNF game.**

BEREA, Ohio (AP) — Cleveland Browns top wide receiver Amari Cooper had to leave Saturday’s practice early with a groin injury and is listed as questionable for Monday night’s game at Pittsburgh.

Coach Kevin Stefanski didn’t have much information on Cooper, who underwent surgery to repair a core muscle injury during the offseason. Cooper was on the field during the portion of practice open to the media.

“We’ll see how he does over the next 48 hours,” Stefanski said.

Cooper led the Browns with 78 catches for 1,160 yards and nine touchdowns last season, his first in Cleveland after four with the Cowboys and four with the Raiders. He played the final weeks despite the core muscle injury.

Cooper briefly came into the locker room following practice but didn’t talk to reporters before leaving.

The 29-year-old Cooper is a major part of Cleveland’s offensive attack and not having him in Pittsburgh would be a huge blow to the Browns (1-0), who are coming off a 24-3 win in Week 1 over Cincinnati.

Cooper left the field in the first half against the Bengals, but said earlier this week he had just “tweaked” something.

Starting safety Juan Thornhill is also listed as questionable with a calf injury that kept him out of the opener. He returned to practice this week for the first time since Sept. 6.