Heat center Alonzo Mourning said Friday he is ready to start over again, just as he started over in training camp after missing 69 games last season with kidney disease.

"I'm tired of sitting out. I'm ready to do one of the things I know best," he said before facing the Dallas Mavericks at AmericanAirlines Arena. He entered to a rousing ovation with 5:48 to play in the first quarter.

Mourning had missed the previous three games because of a virus and an immune system compromised by his kidney illness. Tests taken Wednesday came back Friday at levels that convinced physicians Victor Richards and Gerald Appel a return was allowable.

"They're not to where they were," Mourning said of his levels. "But I got a call from my physicians today and they told me, `We're giving you the OK to play. We don't have any concerns whatsoever. We feel that your playing won't negate you at all from getting you body chemistries back to where they were.' By them giving me the OK, they saw some progress."

Mourning, who closed with 12 points, five rebounds and one blocked shot in 21 minutes off the bench, said he does not know when his levels will return to where they stood before the virus that, in his word, sent his body into "shock."

"It's kind of unfortunate I do have to go through those type of things, but it's a part of the game, and it's something that I have to deal with, and it's something that every kidney patient has to deal with, and that's a suppressed immune system," he said.