Miami recently reassigned longtime assistant coaches Ron Rothstein and Bob McAdoo, and moved Juwan Howard from his player-development role to the bench. David Fizdale, who is seen as a future NBA head coach, will remain Spoelstra's lead assistant.
Smart was out of the league last year after a rough 2012-2013 season in Sacramento, when the team went 28-54. While his teams have struggled when he's been a head coach, Smart was a highly respected assistant in both Cleveland and Golden State.
Rothstein and McAdoo had been hired by Pat Riley, and this is really the first time Spoelstra is assembling his own staff.