BOSTON — Chicago Blackhawks coach Joel Quenneville didn't want to talk about the injury that forced him to scratch forward Marian Hossa from the Stanley Cup finals against the Boston Bruins.

And why not?

"I think that's self-explanatory," Quenneville said, once again declining to explain the secrecy that is as much a part of the NHL culture as playoff beards and Zambonis.

Hossa's surprise scratch from Game 3 and the one-word explanation — "upper" — for the part of his body that was injured is part of a long-running cat-and-mouse game NHL teams play. The theory goes that any revealing information about injuries could become a competitive disadvantage.

Hossa is expected to play in Game 4, Quenneville said Tuesday, but only after making it clear that "I'm not going to get (into) exactly what the injury is or where it occurred."

"It's sort of a secret society in the hockey world and in the injury world," Blackhawks forward Dave Bolland said. "You don't want other teams having any injury information at all."

Asked if he had seen Hossa or had a chance to talk to him, Bolland said, "I don't know."

You don't know if you've seen him or talked to him?

"I don't know if I've seen him," Bolland repeated with a sly smile.

Tuukka Rask stopped 28 shots from the depleted Blackhawks to help the Bruins win 2-0 on Monday night and move two wins from their second Stanley Cup title in three seasons.

Game 4 is Wednesday night in Boston before the series returns to Chicago for a fifth game.

Hossa's mysterious injury may have been a turning point in Game 3, but it's hardly unusual in the secretive world of hockey injuries. Players and coaches say they just don't talk about what's hurting, partly because they don't want to seem weak in a sport where they hit each other for a living.

But mostly they don't want let the other team know where to aim.

"If I'm going out to battle and I have an injury to any part of my body, I don't want the other side to know what it is," Bruins forward Shawn Thornton said.

Injury information can also help the opponent strategize. Quenneville was so concerned about giving the Bruins advance notice of even a few minutes that he didn't let substitute Ben Smith skate in the warmup even though there was a chance he would need to play.

"I just didn't want to tip our hand that there's something going on," the coach said.

"Ben was ready. I knew he was doing everything," Quenneville said. "We were hopeful that Hoss was playing, and Ben was doing everything to get ready. He was ready."

No hard feelings, Bruins coach Claude Julien said. After all, he would do — and has done — the same thing.

"I respect that from other teams. When you're playing against each other, you know exactly where everybody is coming from," Julien said.

"There's times where you have to protect your players, and I understand it. I know it's frustrating for you guys as media. You're trying to share that information. The most important thing for us, we can take the heat for that, is protecting your players."

So, how to tell if an injury is minor? When a team actually admits it exists.

"I'll share one with you: Yesterday in a warmup, Zdeno Chara fell down, got a cut over the eye," Julien said, to laughter, of the injury to his captain that had already been confirmed and reported. "I'll let you know about that. That's not a hidden injury."

The Bruins also confirmed without delay the broken leg that knocked Gregory Campbell out of the Eastern Conference finals against Pittsburgh. But that was only because Campbell was out for the season after taking a shot to his leg on national TV and struggling to get off the ice.

"If it's something that doesn't put your player in danger, I don't see why you shouldn't talk about it," Julien said.

Players say they don't have to be told not to discuss injuries; they grow up with the culture in junior and minor leagues. Blackhawks forward Patrick Sharp said he doesn't remember when he first learned the subject was off-limits, but it was long before he reached the NHL.

And hockey players are not alone.

"It's not just here," Thornton said. "I don't think Bill Belichick is (listing) all the injuries they have, either."

But even the notoriously uncommunicative New England Patriots coach is required by NFL rules to say what body part is injured. NHL coaches have to narrow it only to "upper body" or "lower body," which means a player with a concussion and one with a broken finger would have the same diagnosis.

During the playoffs, information is even more scarce.

"It's that time of year where everybody's kind of battling. I would say that not just injuries, strategy, all that kind of information we're not going to talk about," Sharp said. "It's all part of being this close to the ultimate goal."

And does he have any injuries he cares to mention?

"No comment."