Memphis Grizzlies guard Jordan Adams is undergoing cartilage transplant surgery on his right knee.The Grizzlies announced the transplant was being performed Wednesday at the Hospital for Special Surgery in New York by Dr. Riley Williams.Adams, 21, underwent a lateral meniscectomy on the same knee last August after sustaining a partially torn meniscus during an offseason workout.Adams was sidelined for most of the summer and limited in training camp. He returned to play for a short period before suffering an unrelated injury to the articular cartilage in his right knee. Adams subsequently underwent a debridement surgery on Jan. 12.Following that surgery, Adams participated in a lengthy rehab program -- extending through the second half of the 2015-16 season -- in an effort to resume basketball activities. He was ultimately unable to return to contact play without pain in his right knee.The team's medical staff determined that a cartilage transplant was in his best interests. Adams will be out indefinitely."This is obviously difficult news for Jordan and our organization," Grizzlies general manager Chris Wallace said in a statement. "Jordan has been on a tough road for the better part of a year. We wish him a full and speedy recovery and hope that this procedure will help him return to the hardwood."The 6-foot-5, 209-pound Adams holds career averages of 3.2 points and 0.9 rebounds in 8.2 minutes in 32 games (no starts) since he was selected by Memphis in the first round (22nd overall) of the 2014 NBA draft following his sophomore season at UCLA. The Atlanta native appeared in two games in the 2015-16 season.