Cleveland Cavaliers guard Kyrie Irving is doubtful for Friday's game against Memphis because of an undisclosed illness.

Irving returned Monday after a three-game absence because of a hyperextended right knee. He is averaging 23.2 points and 5.7 assists in 47 games this season.

The Cavs have also listed guards Dion Waiters and Daniel Gibson as probable for Friday's game. Waiters has missed two games because an illness, while Gibson missed Wednesday's game against Utah with an illness.