Tony Romo’s season is done.

A CT scan Friday morning confirmed that the Cowboys quarterback suffered a hairline fracture in his left collarbone in the vicinity of the previous break. Surgery is not required, but for the third time in the last six years Romo is unable to finish a season due to injury.

Romo managed to start only four games, his lowest total since he became the franchise’s starting quarterback during the 2006 season. He was 83-of-121 for 884 yards with five touchdowns and seven interceptions in those games.

The injury means Matt Cassel, who went 0-4 during Romo’s initial absence, will be entrusted with finishing out this 3-8 season. Cassel’s struggle underscores the fact a backup quarterback hasn’t won a game for the Cowboys since Stephen McGee did so at the end of the ’10 season.

Kellen Moore, currently on the team’s practice squad, will likely be signed to take Romo’s place on the roster.

The concern in recent seasons has been Romo’s back. But this is the second time a broken collarbone has knocked him out for the majority of the season. The first came in ’10 season when missed the final 10 games.

That injury, like the two this season, came on the left side.

Romo went down for the first time this season in Week 2 when Philadelphia linebacker Jordan Hicks landed on top of the quarterback and drove his left shoulder into the turf. He suffered a distal clavicle fracture and was placed on the injured/designated return list, missing seven games.

Romo was injured Thursday on the final play of the third quarter on a sack by Carolina linebacker Thomas Davis.

Foles likely to start

Unless Case Keenum passes the NFL concussion protocol Saturday, St. Louis will turn to benched starter Nick Foles at quarterback.

Keenum split practice time Friday with Foles, who was relieved of his duties two weeks ago by coach Jeff Fisher. Keenum had returned to practice on a limited basis Wednesday after missing Tuesday’s workout because of a concussion.

“At this point, Case has been limited in practice and we’ve got him listed as questionable,” Fisher said after practice. “He’s not quite cleared the concussion protocol and unless we get good news tomorrow, then Nick will be our starter. If he’s completely cleared, and if he feels good, he’ll start.

“As it is right now, it’s looking like we’re going to have to potentially go with Nick, which is great. I’m so excited about Nick getting a chance to play. Case might be our third unless things get better tomorrow.”

Revis to sit out Sunday

Revis Island is closed for the weekend.

Cornerback Darrelle Revis will not play in the New York Jets’ game against the Miami Dolphins on Sunday because he is still dealing with a concussion. He remains in the NFL’s concussion protocol and must be cleared by doctors before he can practice with the team.

Revis was injured during the Jets’ 24-17 loss at Houston last Sunday and has not practiced since.