(Reuters) - Dallas Cowboys quarterback Tony Romo has had season-ending back surgery on an injury suffered in last Sunday's game against the Washington Redskins, head coach Jason Garrett said on Friday.
Back-up quarterback Kyle Orton, who has played only two games this season, will start this Sunday's crucial clash with the Philadelphia Eagles in which the winner will qualify for the NFL playoffs and the loser's season will be over.
"He's devastated," Garrett said of Romo. "He put a lot into this."
The Cowboys had earlier hoped the standout quarterback would be able to play on Sunday.
"We spent the week exhausting all options - treatment, rehab, all the different things - consulted a lot of people and we felt this was the best decision for him and our organization and we felt it was better to have this done sooner rather than later," Garrett told reporters.
"We felt like the surgery went well and Tony should be able to come home hopefully later today and start his rehabilitation for the 2013-14 season."
Cowboys owner and general manager Jerry Jones said he expected Romo back for pre-season team activities and the surgery would not force him to use an early-round pick on a quarterback in May's NFL draft.
"With my expectation of Tony's career, which I think will be for several years to come, it's too early to be drafting a highly ranked or, if you will, costly quarterback," Jones told Texas radio station KRLD-FM.
The surgery was Romo's second in eight months. He underwent a procedure in April to remove a cyst.
"They were unrelated," Garrett said. "Obviously he (Romo) played very well coming off the first procedure he had in the spring, so we're completely confident he's going to rehab and come back 100 percent."
Romo, 33, has played 136 games for the Cowboys since 2004, completing 64.6 percent of his passes and helping his team to the playoffs in 2006, '07 and '09.
Apart from his back problems, other injuries have included a broken collarbone, broken ribs and a punctured lung.
Although Orton has hardly played this year, completing three of five passes, he is no NFL novice, having started in 69 regular season games with Chicago and Denver, going 35-34.
Dallas has signed 41-year-old Jon Kitna to be Orton's back-up against the Eagles.
Kitna, who spent 15 years in the NFL and last played in 2011, has said he will donate his $53,000 salary from the game to the Washington state high school where he teaches.
(Reporting by Andrew Both in Cary, North Carolina, editing by Gene Cherry)