MIAMI — Forward Shawn Marion was not in Miami's starting lineup for tonight's game against the Orlando Magic because of a back injury, making him the latest Heat player to join the ranks of the injured.

Alexander Johnson started in Marion's place.

Marion said he aggravated the back problem earlier this week, and played with soreness Wednesday night against the New York Knicks. He still expects to be in the starting lineup Sunday against the Dallas Mavericks.

"I don't want to sit here and have it keep nagging," Marion said. "If I can take a day off and get it right, it isn't going to kill me."

Marion has been one of the NBA's most-dependable players, having missed just 12 regular-season games in his last seven full seasons.

Without Marion, the Heat would be down, once again, to eight healthy players. Dwyane Wade, Alonzo Mourning and Dorell Wright are all out for the season with knee problems, and Miami is also playing without Udonis Haslem (ankle), Marcus Banks (hamstring) and Earl Barron (knee).