The moves pare Oklahoma City’s training camp roster to 16 players.
Gaddy saw spot duty in four preseason games. He has mostly played overseas since going undrafted out of Washington in 2013.
Grantham, Hopson and Wells were signed earlier this week. All could wind up with the team’s G League affiliate, the Oklahoma City Blue, once they clear waivers.
Grantham was averaging a career-best 14.2 PPG and 6.9 RPG for Clemson last season before tearing his ACL in January.
Hopson played in Turkey last season, averaging 11.1 PPG and 3.6 RPG in 27 games with Galatasaray. He played one game with the Mavericks last year after signing a 10-day contract in February and played two games for the Cavaliers in 2013/14.
Wells played in Italy last season, averaging 11.3 PPG and 2.7 RPG in 52 games with Sidigas Avellino.