Coach Mike Babcock announced Friday that Gustavsson will start Game 5 in Boston with Jimmy Howard still out with an illness. Boston leads the best-of-seven series 3-1.
"Gus is going to start," Babcock said. "Obviously [Howard] wasn't able to practice today. I assume he'll be the backup."
Gustavsson made 37 saves in Game 4's overtime loss after getting notice that he was starting during warmups. It was his first NHL postseason start.
Veteran forward Daniel Alfredsson, who has missed two consecutive games because of an injury, practiced and said he felt well. He'll be available for Saturday's potential elimination game, although Babcock said he hadn't settled on a potential lineup.