CLEVELAND -- Cavaliers rookie forward Anthony Bennett of Brampton, Ont., the top pick in this year's NBA draft, has asthma and sleep apnea.

Cleveland coach Mike Brown revealed Bennett's conditions Thursday night before the Cavs hosted the Detroit Pistons in an exhibition game. Bennett's asthma was not widely known and obviously did not prevent the Cavs from taking the former UNLV star in June's draft.

Bennett has had some breathing issues during workouts and in preseason games, and him being sometimes winded had been attributed to him not being able to work out as much this summer after undergoing shoulder surgery in May. But Brown said Bennett also deals with asthma and wears a mask at night for his sleep apnea.

"It's a culmination of a lot of things," Brown said. "The shoulder, he's been out for a while, he's got asthma. We're throwing a lot at him. He's probably never played this hard against this competition in his life. He's got sleep apnea and some other things. He likes to stay up late."

The 6-foot-8, 259-pound Bennett averaged 10 points and 6.3 rebounds in his first three NBA preseason games. He's coming off the bench for Brown, and made his first shot -- a 3-pointer -- against the Pistons and followed that up with a breakaway dunk.

Brown said Bennett's breathing issues are noticeable.

"It's been tiring to watch him because every time I watch him he's (gasping)," Brown said. "It makes me tired, so I try not to look at him. I tell him, 'If you need a sub, just tell me. Otherwise I'm not going to look at you."'

Bennett was not in Cleveland's locker room during the period it was open for media members.