Owner and general manager Jerry Jones said the initial diagnosis was a dislocation. Lee, the Cowboys' leading tackler, suffered the injury on the final play of the first quarter of Sunday night's loss 34-7 loss in Philadelphia when his wrist was bent backward while attempting to tackle Eagles quarterback Michael Vick.
"I'm hoping I could play next week," said Lee, who had his wrist in a brace after the game. "I couldn't return tonight. The doctors would not let me out there. Hopefully I can get it re-evaluated and it'll be all right."
Any absence from Lee would hurt the defense. Entering Sunday's game the coaches had credited Lee with 72 tackles, 41 more than any other defender. He also has a team-leading three interceptions and recovered two fumbles.
Before his injury, the Cowboys' defense struggled but it got worse in Lee's absence. Brooking and James struggled in containing Eagles running back LeSean McCoy and were beat in coverage too.
Depth would be an issue, too. Rookie second-round pick Bruce Carter made his season debut against the Eagles, but the plan was to ease him into the lineup on special teams. Without Lee, Carter could be called on more quickly than anticipated to help in pass coverage.
The Cowboys lost another defensive starter for the night after cornerback Mike Jenkins suffered a hamstring injury in the third quarter.
Jenkins had been bothered earlier in the year with a stinger injury suffered in training camp and a shoulder injury suffered in the season opener, but he had not missed a game.
He was replaced by Orlando Scandrick.
Meanwhile, punter Mat McBriar left the game with a left foot injury.
Todd Archer covers the Cowboys for ESPNDallas.com.