Coach Josh Pastner said in a release that Pellom underwent arthroscopic debridement surgery Thursday. Pastner called it "a simple and minor procedure."
Pellom, 6-foot-7, had been experiencing knee discomfort from an injury he sustained earlier in his career.
The George Washington transfer missed the entire 2012-13 season with a wrist injury. He averaged 10.4 points and 6.1 rebounds per game for George Washington while ranking fourth nationally with a .685 field-goal percentage in the 2011-12 season.
No. 13 Memphis opens its season Nov. 14 against Austin Peay.