Tony Romo could miss most of the NFL season after the Dallas Cowboys confirmed the quarterback has a broken bone in his back.
Romo suffered the injury when he took a hit to his back on the third play of the Cowboys' preseason clash with the Seattle Seahawks on Thursday.
There is no timetable for Romo's return but he is reportedly expected to miss between six to 10 weeks of the season.
Romo has been dogged by injuries in recent times, he played in just four games last season after twice breaking his collarbone. A broken bone in his back forced Romo to miss time in 2014 and surgery on another back problem saw the 36-year-old sit out the final game of the 2013 campaign.
Dallas coach Jason Garrett said: "We're going to monitor his condition day by day and we'll see how he feels going forward. There's no timeframe when he's going to return."
With Romo out, the Cowboys will be in the hands of rookie QB Dak Prescott, who has dazzled in the preseason.
The fourth-round pick out of Mississippi State has completed 39 of 50 passes for 454 yards, with no interceptions. He has five passing touchdowns, two rushing touchdowns, and an NFL-leading passer rating of 137.8.