MacDonald, 33, has yet to play this season due to a back injury. He split last season between the Red Wings and their American Hockey League team, the Grand Rapids Griffins. In 14 NHL games, he went 8-5-1 with a 2.16 goals-against average and .912 save percentage.
Long-time Flames top goalie Miikka Kiprusoff is on injured reserve with a lower-body injury. Leland Irving has started the last two games, going 1-1-0 while allowing eight goals on 60 shots. His backup, Daniel Taylor, has played one NHL game, for the Los Angeles Kings in the 2007-08 season.
The Flames also placed forward Michael Cammalleri on injured reserve (retroactive to Feb. 5). The Calgary Sun is reporting Cammalleri his a hip pointer injury.