FRISCO, Texas -- Just as the Dallas Cowboys received good news regarding the health of wide receiver Amari Cooper's left knee following Thursday's loss to the Buffalo Bills, the team lost left guard Connor Williams to a torn anterior cruciate ligament in his right knee.

Williams left the game in the second quarter after an Ezekiel Elliott run, but returned for the opening series of the third quarter only to be pulled after a false start. An MRI confirmed the tear. Williams did not play Nov. 17 against the Detroit Lions after undergoing arthroscopic surgery on his left knee, but he returned to play Nov. 24 against New England.

Jason Garrett said Williams will have surgery in the next two to four weeks.

Xavier Su'a-Filo, who replaced Williams against the Lions and on Thursday, will move into the starting lineup. Su'a-Filo started eight games last year replacing an injured Williams.

Cooper suffered an injury in the fourth quarter when he took a helmet to his left leg after making a catch. He was able to return to the game and further tests showed no structural damage, according to sources.

Cooper has played through heel, ankle and quadriceps injuries throughout the season but has not missed a game.