Dwyane Wade also has been dealing with the flu but played.
All three players missed the Heat's shootaround Friday morning.
The flu has affected the Heat throughout the season.
Team president Pat Riley missed Miami's recent visit to the White House because of the illness. Bosh has been fighting it for much of this week and also missed Wednesday's game against the Houston Rockets.
"I feel different each day," said Heat forward LeBron James, who has battled congestion this week. "Just try to get as much vitamin C, just try to take your vitamins, just try to stay on course and not let it affect you."
There was one roster move the Heat made Friday that wasn't illness-related: They signed forward-center Chris Andersen for the remainder of the season, as has been expected since they brought him into the organization three weeks ago.
Information from The Associated Press was used in this report.