Jones broke loose on a 40-yard run early in the third quarter to set up a field goal but was hurt at the end of the run.
Jones rushed for 94 yards on eight carries and also had a 20- yard reception before leaving the game. Further tests on Tuesday showed Jones has a sprained PCL, and his status for Sunday's game versus the Denver Broncos is undetermined.
The Cowboys were already missing starting running back Marion Barber, who is battling a quadriceps injury. Barber didn't play on Monday and his status is also questionable for Sunday.
Tashard Choice is the only healthy tailback right now for Dallas. Choice rushed for 118 yards and a touchdown Monday.