Long suffered the injury on the opening possession of Nebraska's 44-7 win against Purdue, getting tripped up while blocking on a run by Imani Cross. The surgery is scheduled for Thursday, and it will end his season.
Long, a former walk-on, ranks third on the team in career starts, trailing only to tackle Jeremiah Sirles and quarterback Taylor Martinez. Long earned first-team All-Big Ten honors from the media and coaches in 2012, even making the AP's All-America second team.
With Long out, Nebraska is expected to try several different options to complete replace him on the senior-laden offensive line. Starting center Cole Pensick has some experience at guard, but junior Mike Moudy, Long's listed backup, played the remainder of the game against Purdue.
Nebraska is off this week, hitting the road to face Minnesota next on Oct. 26.