Court records in Cleveland Country District Court accuse Reed of breaking into his ex-girlfriend's apartment at 3:31 a.m. Sunday and assaulting both the woman and another man.
"He is suspended indefinitely while the matter is pending, per OU policy," school spokesman Pete Moris said in a statement to the Associated Press.
Reed played in just one game for the Sooners in 2012, though he was listed as the No. 2 left tackle on Oklahoma's depth chart for game week. Redshirt junior Tyrus Thompson, a starter in five games and participant in all 13 contests last year, is the listed starter.
The Sooners kick off the 2013 season against Louisiana-Monroe on Aug. 31. Bob Stoops named redshirt freshman Trevor Knight the starting quarterback for the game after a lengthy competition, though many expect Blake Bell to continue his work in specialized offensive packages. With the Warhawks using their own two-quarterback attack, the matchup is one of few contests this weekend to all-but-guarantee the use four different quarterbacks.