Wagner missed the entire preseason and the first 33 games of the regular season after undergoing right knee surgery on Nov. 4. The 6 foot 2 inch guard has been plagued by injuries since the Cavs made him the sixth overall pick of the 2002 NBA draft.
During last season's training camp, he had surgery to remove a blood clot resulting from a bladder infection and missed the first 14 games.
Wagner averaged 13.4 points and 2.8 assists in 47 games as a rookie. He had surgery March 21 to repair torn cartilage in the knee and missed the final 20 games of the season.
Diop was placed on the injured list on Dec. 8 after undergoing surgery to repair a torn lateral meniscus in his right knee, and has missed Cleveland's last 16 games. Selected eighth overall in 2001, the 7-foot center has been a major disappointment with the Cavaliers.
Diop is averaging 2.8 points per game in 16 contests this season, a point more than his 1.7 career average.
The Cavaliers placed forward Ira Newble and center Bruno Sundov on the injured list to make room for Wagner and Diop on the roster. Newble has missed the last two games with a right quadriceps contusion and Sundov has right Achilles tendinitis.
Dennis Rodman pledges to end trips to North Korea
Teacher apologizes for showing sexual image of herself in class