Indianapolis Colts quarterback Andrew Luck has been playing with multiple fractured ribs, according to Jay Glazer of FOX Sports.
The ribs were broken at the same time Luck injured his shoulder in Week 3, Glazer reported Sunday.
Luck has never been disclosed on the injury reports as having injured ribs.
"To Luck's credit he's tried to quietly fight through it but clearly the combination has affected him," Glazer wrote on Twitter.
Luck, who missed games in Weeks 4 and 5 with what was reported at the time as a shoulder injury, has struggled since his return.
Luck ranks 30th in the NFL in passer rating (76.3) as the Colts face the Carolina Panthers on Monday night.
"I'd say I'm frustrated," Luck said after the loss to the New Orleans Saints last Sunday. "I think, as an (offensive) unit, we're frustrated and I'm frustrated with myself. Some egregious turnovers. It's really bad football. We'll come to work and start working to fix it."