BOSTON — The Chicago Blackhawks needed all their offensive weapons against the Bruins' smothering defense and goalie Tuukka Rask. Instead, they lost one of their best before the game.

Marian Hossa was a late scratch with an upper body injury before Game 3 of the Stanley Cup finals, and the Blackhawks lost 2-0, falling behind Boston 2-1 in the best-of-seven series Monday night.

Hossa's status for Game 4 on Wednesday night was uncertain.

"We'll say day-to-day. We're hopeful he'll be ready for the next game," Chicago coach Joel Quenneville said. "It was a game-time decision after the warm-up there. That's when we made the call."

The Blackhawks had tweeted that Hossa was "out of the lineup after something apparently happened in warm-ups." But, Quenneville said, "Nothing happened during warm-up."

Hossa has three game-winning goals in this postseason and was third on the team with 15 playoff points. In his 14 NHL seasons, he scored at least 25 goals 11 times.

And he already had made a big play in this series.

With Chicago trailing 2-0 in Game 1, Hossa stole the puck from Dennis Seidenberg in the Boston end and fed Brandon Saad, who one-timed it past Rask at 3:08 of the second period. The Blackhawks rallied from a 3-1 deficit in the third period and won 4-3 in three overtimes.

Hossa's replacement appeared in his first playoff game this year.

Ben Smith was a veteran of just 20 regular-season games and seven playoff games in his three NHL seasons before being pressed into action. But he figures he played about 15 times at TD Garden with Boston College.

"I was a little surprised because you don't know what's going on, but you don't ask any questions," he said. "You get a chance, you go."

He certainly didn't expect it.

"I was here and ready to ride the bike and work out," Smith said. "They gave me the tap and said, 'Go with it.'"

Quenneville hoped Smith could provide a spark.

"Benny gives us energy," he said. "He's one of those players that offensively, defensively, he's responsible. He's been practicing hard."

But Hossa's absence removed one of the few productive players on the Blackhawks sputtering power play. They were scoreless in five opportunities in the game and in their last 20 man-advantage situations in the playoffs.

Hossa has three of their 16 power-play goals in the postseason.

"Our power play tonight was definitely not good," Quenneville said. "They box you out. They got big bodies. They blocked shots. I think we had some chances to get some pucks through the net. We didn't. Our entries weren't great. That's something you want to look at."

"It's frustrating," Chicago defenseman Duncan Keith said. "We just need to go out and play and let our skill take over."

They've had a tough time against Rask, just as the Toronto Maple Leafs, the New York Rangers and Pittsburgh Penguins did in the Bruins previous three series.

Rask has stopped 61 of 62 shots in the last two games and 120 of 125 in the series.

Bruins coach Claude Julien didn't find out his team wouldn't have to deal with Hossa until just before the game.

"I was surprised as anybody else," he said, "but, to be honest with you, there weren't any changes in our game. As I mentioned the other day when I was asked about another player, we don't make our game plan based on an individual.

"I can definitely tell you they lost a pretty important player on their roster, but that doesn't mean we change our game. I think it's important we stick with what we believe in."

They believe the key to winning in the playoffs is disciplined and persistent checking, precise passing and steady, if not spectacular, goaltending.

They Blackhawks have been stymied by all of that.

"It's a low-chance game. It's a low-chance series," Quenneville said. "It's hard to get A-plus chances. You have to manufacture the second, kind of ugly goals, tip screens, deflections."

That's tough to do.

Without Hossa, it's even tougher.