The Dallas Cowboys will play the rest of the NFL 2013 season without defensive end Anthony Spencer as he is scheduled undergo surgery on his left knee, according to his agent Jordan Woy.
Earlier, team owner/general manager Jerry Jones said that Spencer might need microfracture surgery, though it was unclear later whether he would have that procedure.
"It's a real setback," Jones said on his radio show on KRLD-FM.
According to team physician, Spencer is expected to be 100 percent by January or February.
Spencer underwent surgery on the troublesome knee July 25 and has practiced fewer than five times and played in just one game, the Week 2 road loss to the Kansas City Chiefs.
The plan was for Spencer to play on third downs only against the Chiefs, but he played 34 snaps and had two tackles and one quarterback hurry.
The next day, Spencer reported soreness in his knee but thought it was normal after playing in a game for the first time this season.
When the knee didn't respond to treatment, the Cowboys ruled Spencer out of the Week 3 game against the St. Louis Rams.
Spencer said his knee was sore the morning of the Rams game, and it prevented him from trying to participate in pregame warm-ups.
The Cowboys franchised Spencer, costing them $10.6 million, instead of allowing him to test the free-agent market in the offseason.
He was coming off a season in which he had a career-high 11 sacks and was named to the Pro Bowl as an injury replacement for Green Bay Packers linebacker Clay Matthews.