On Wednesday, he underwent a successful scope of his left knee, according to the Thunder.
With the six-to-eight week timetable for recovery from this surgery, it's unlikely that George would miss any significant offseason activity that would deter a team from signing him.
George posted an image on his Instagram story prior to the surgery taking place on Wednesday with the caption "Good Spirits".
The Thunder later confirmed his knee procedure. He also missed a game earlier this season with left knee soreness.
George dealt with a number of injuries this season, including "forearm tightness" and a hip injury that appeared to limit him in the playoffs against the Jazz.
George, 28, had a stellar initial season with Oklahoma City, recording an average of 21.9 points on 40 percent shooting from distance.
George has a player option for $20.7 million for this season, but is expected to decline it to become one of the offseason's most highly pursued free agents.