The school described the injury as a "foot strain" and said the 7-foot-2 sophomore is expected to be ready for the Nov. 6 season opener against Northern Arizona.
Clingan averaged 6.9 points and 5.6 rebounds and 1.8 blocks per game as a freshman in helping the Huskies (31-8) to the program's fifth NCAA championship.
Clingan spent last season backing up Adama Sanogo -- the most outstanding player in the NCAA tournament -- who left for the NBA after last season.
Coach Dan Hurley said this week that he expects Clingan to be a key to his offense this season, as well as a team leader.
"The evolution for him is to demand the ball and demand that his teammates play up to a certain level," Hurley said. "I mean, sometimes you've got to be the bad guy, too. You just can't be kind of the jolly giant. Sometimes you've got to be the angry giant."