Diop is expected to miss four to six weeks after undergoing surgery on Thursday to repair a torn lateral meniscus in his right knee.
Selected eighth overall in 2001, Diop has been a major disappointment with the Cavaliers. He is averaging 2.8 points per game in 16 contests this seaosn, a point more than his 1.7 career average.
Sundov has been sidelined since November 28 with a right wrist contusion. He has played in three games this season and is averaging 2.3 points.