While there had been an inkling Zetterberg could play in Game 4, Detroit's biggest surprise was goaltender Jonas Gustavsson's insertion into the starting lineup in place of Jimmy Howard, who the team said is out with the flu.
Gustavsson, making his NHL postseason debut, was 16-5-4 for the Red Wings this season, with a .907 save percentage.
Zetterberg, who hasn't played since leaving the Winter Olympics early to have back surgery, was officially listed as a game-time decision prior to Thursday night's game against Boston.
On Wednesday, he skated in the place of Pavel Datsyuk, whose wife was having a baby, and declined to put a timeline on his return.
Zetterberg skated again Thursday -- this time on a line with Datsyuk and Justin Abdelkader. Red Wings coach Mike Babcock said he worked him into the power play.
After practicing, Zetterberg left to meet with doctors to determine his availability against the Bruins.
The Red Wings coach tried to manage expectations for Zetterberg's 2014 postseason debut.
"I can expect him to provide great leadership both in the room and on the ice," he said. "If we get nothing else, that's good enough."
The Bruins lead the Red Wings 2-1 in the best-of-seven first-round playoff series.