Alonzo Mourning remains fixed on returning to the Nets, but how effective he will be is very uncertain.

Mourning, who signed a four-year, $22.6 million contract, has worked out furiously and consulted often with his physician, Dr. Gerald Appel, the director of nephrology at Columbia Presbyterian Medical Center. Dr. Appel said that doctors were working to devise a plastic shield to protect the kidney, but that they could not predict the future for Mourning.

"He'll have a protective device in front of it to reduce the risk of trauma," Dr. Appel said. "He'll have to stay well hydrated. He can play good ball. He's in good shape. The only question is what's for the future. He can always have a rejection episode. We can't guarantee there will be no complications."

If Mourning plays fewer than three games next season, the Nets can apply to have his salary removed from their cap next summer.  With that duly noted, it is likely that Mourning will be pressured to be as certain as he can that he will be healthy throughout the season, before that fourth game.