DALLAS -- Dallas Cowboys defensive end Anthony Spencer may need microfracture surgery, which would mean an end to his season.
Cowboys owner Jerry Jones delivered the stunning news on his radio show on KRLD-FM Tuesday.
"It's a real setback," Jones said. "It looks as though it could be for the year."
Spencer and his agent, Jordan Woy, are meeting with doctors Tuesday.
"At this point, we are confident he will be 100-percent healthy for next season," Woy said.
Spencer missed most of training camp in Oxnard with what was called a bone bruise. He had surgery on the knee July 25.
The 29-year-old played 34 defensive snaps against the Chiefs in Week 2 and expected to again have a limited role against the Rams, but the knee failed to respond well to treatment and the Cowboys held him out.
Monday, Cowboys head coach Jason Garrett was optimistic about Spencer's return to the field this season.
For the second straight year, the Cowboys used their franchise tag on Spencer, meaning his salary is $10.6 million this season and he'll be a free agent at the end of the year.
He had his best year as a pro last year, earning his first trip to the Pro Bowl.
This latest injury news means he'll likely find a better deal in the free agent market than the Cowboys are willing to offer.