Dallas Cowboys starting middle linebacker Sean Lee has been ruled out for Sunday's win-or-go-home game against the Philadelphia Eagles, a source close to the situation told ESPN NFL Insider Adam Schefter.
Lee's sprained neck, suffered against Chicago on Dec. 9, is more significant than originally thought, according to the source.
He has missed the Cowboys' previous two games with the injury and had been hopeful he could return for the regular-season finale.
Lee, called the quarterback of the defense by defensive coordinator Monte Kiffin, missed two games in late November with a hamstring injury.
Information from ESPNDallas.com's Calvin Watkins was used in this report.