Andrew Luck is likely to miss the Indianapolis Colts' season opener with the Los Angeles Rams, according to team owner Jim Irsay.
The Colts' star quarterback underwent labrum surgery in January and, while Irsay said there have been no setbacks with the injury, Luck has been unable to practice and kept on the Physically Unable to Perform (PUP) list.
Speaking after the Colts' preseason finale with the Cincinnati Bengals on Thursday, Irsay said: "The odds are most likely he probably won't open up against the Rams.
"But let me be clear about it: in our own minds, it's something we haven't ruled out."
The Colts have until 16:00 EST (20:00 GMT) to either leave Luck on the PUP list or add him to the active roster. Should Luck start the season on the PUP, he will be unable to play for the first six weeks of the campaign.
Irsay, though, says Luck believes he will return from injury a better player.
"From when him and I have talked it has been 'Mr. Irsay, let me be clear. When I come back I'm going to be the best football player that I have ever been. I can promise you that. It's just that I don't know exactly when that date's going to be,'" Irsay said.
"But that's the type of confidence that he has. He really feels good about getting this thing fixed and going forward.'"
Scott Tolzien would be poised to start at quarterback in the September 10 opener if Luck is not able to play.