His lone communication with the team in several days has been through text messaging.
"It's unfortunate because we're going through a major playoff push right now," Heat coach Erik Spoelstra said Monday. "And what we've emphasized since the very first day of training camp is purity. You're either in or you're out. And I guess he's declared that he's out. So we know who our group is now."
Spoelstra said the Heat have spent the past few days deciding who, if anyone, they would sign to replace Alston, who remains on the roster. Without him, the Heat have only two point guards, Carlos Arroyo and Mario Chalmers, though Dwyane Wade logs plenty of minutes at the position.
Alston has not responded to requests for comment. He said before Thursday's game against the Los Angeles Lakers that he had been removed from the starting lineup, but gave no indication he planned to leave the team.
The Heat entered Monday holding the No. 7 spot in the Eastern Conference playoff race, 1½ games behind No. 5 Milwaukee and a game ahead of No. 9 Charlotte. Miami visits the Bobcats on Tuesday night.
"We've got games to play," Wade said. "We've got to focus on who's here and what we're doing."
Alston started March 2 against Golden State, played the first 6½ minutes, then appeared to be upset when taken out. He did not play again in that game nor in Thursday's game against the Lakers.
He was not at the arena for Saturday's win over Atlanta, and the Heat announced his suspension about two hours after the game.
"I really don't know what's going on," Heat forward Udonis Haslem said. "I just know I haven't seen him. It's not really a distraction. Nobody knows anything about that situation. I know we've won three in a row and we've got to move forward."