The Dallas Cowboys have put Jon Kitna on injured reserve, ending the quarterback's 15th NFL season and possibly his career.
The 39-year-old Kitna, in his third season as Tony Romo's backup, hasn't played since Nov. 13 because of a back injury.
Kitna's most extensive action with Dallas came last season after Romo broke his collarbone. In 10 games, Kitna threw for 2,365 yards with 16 touchdowns and 12 interceptions.
Kitna has thrown for 29,745 yards with 169 TDs and 165 interceptions in 141 NFL games with Seattle, Cincinnati, Detroit and Dallas.
The Associated Press contributed to this report.