Cavaliers center Andrew Bynum took part in some of practice on Sunday afternoon at Cleveland Clinic Courts, including some five-on-five up-and-down the court, according to coach Mike Brown. But Brown said Bynum has not been cleared to take part in a full practice or play in a game. "There's parts of the practice they don't want him to do,'' Brown said, referring to the team's medical staff. "He hasn't participated in every aspect of practice all the time.'' Still, the coach stopped short of saying that the fact that Bynum had not taken part in a full practice as of Sunday afternoon would rule him out of playing in Wednesday's season opener against the visiting Brooklyn Nets. "I'm not even speculating that,'' Brown said Sunday. "What I'm waiting for is the doctors to say he can play. If the doctors say he can play, that's when I'll make a decision as to whether or not to play him. But the doctors have not cleared him to play yet.'' There has been much speculation about Bynum's availability since Brown said 10 days ago that the center was ''close'' to returning to practice. Clearly, Bynum has been working hard and increasing his workload, as was evident in a strenuous pre-game workout he did on the court at The Q before the Cavs played the Detroit Pistons on Oct. 17. But the Cavs have emphasized that they would be cautious with the return of the big man who missed all of last season and had surgery on both knees in March before signing a two-year contract last summer. Throughout training camp, the team has said there was no timetable for Bynum's return, a sentiment Bynum echoed on media day Sept. 29 in his only comments to reporters thus far. As far as any injury to any player, the team always has erred on the side of caution. Brown's comment about deciding whether Bynum will play once he is cleared by doctors is further evidence. Presumably, Bynum would have to take part in a full practice before he's cleared for a game, and players who have suffered significant injuries -- like Anderson Varejao, who missed most of last season with a quadriceps injury and resultant blood clot -- have talked about the time it takes to get one's rhythm and timing back. Bynum, of course, is not the only injured Cav trying to return. Center Tyler Zeller, who had a hip injury at the start of camp and then an appendectomy, took part in all of Sunday's practice and looked fine, Brown said, but has not been cleared to play. Rookie Sergey Karasev, who suffered a sprained left ankle in Monday's victory over Philadelphia in Columbus, did parts of practice on Sunday.