Hours before the Stanley Cup finals began, NHL commissioner Gary Bettman proudly proclaimed that concussions are down across the league and there are numbers to back him up.

That does not mean the league has figured out how to prevent head injuries among its players. Or that the numbers tell the whole story.

According to data from STATS provided to The Associated Press, there were 53 concussions during the regular season, a sharp decline from the 78 reported during the league's last full season two years ago.

The Canadiens were criticized for letting Dale Weise return after a blindside hit, but GM Marc Bergevin insisted the team did not know Weise had a concussion until the next day and that the league's protocol was followed. Eric Bolte/USA TODAY Sports

But even Bettman said there is only so much the league can do about a player hiding a head injury to stay on the ice.

"Obviously, it's difficult for us to get into a player's head, no pun intended, with this concussion discussion," he said. "But if a player is going to not follow the protocol, not say exactly what he's feeling, that's pretty difficult to address."

Dr. Jeff Kutcher, an Ann Arbor, Michigan-based neurologist who works with NHL players believed to have concussions, wasn't sure the lower numbers indicated a dramatic change.

"I'm not surprised that the numbers are down, but I wouldn't read too much into those numbers," Kutcher said.

The NHL's concussion protocol, like other leagues, requires players to get a team doctor's OK before they can return to play. They are taken to a quiet place for evaluation, questions and tests of their memory, balance and general awareness.

Players, though, seem to be able to skate around the protocol.

Columbus Blue Jackets defenseman James Wisniewski said he avoided return-to-play protocol after he went head first into the boards during the playoffs. He wanted to keep playing.

The Montreal Canadiens were criticized for letting forward Dale Weise return to Game 5 of the Eastern Conference finals after a blindside hit sent him to the dressing room. General manager Marc Bergevin insisted the team did not know Weise had a concussion until the next day and that the league's protocol was followed.

"It's flawed, but I'm not a doctor," Bergevin said. "We all worry about our players, but we can only go by what we're given."

Hockey Hall of Famer Brendan Shanahan, who was hired by the Toronto Maple Leafs to be their president two months ago after he was the NHL's chief disciplinarian, said it is good for the game that concussions are part of the conversation.

"When there are situations like we've had in the playoffs, whether it is a hit to the head or mis-reporting, it gets put in the spotlight and it should," Shanahan said. "That is part of the continuing change of culture, and it's going to be an ongoing process. I don't think there ever will be a perfect system because players are always going to want to play."

The NHL Players Association says it has taken steps to educate its players about the dangers of concussions, including bringing doctors to each team before the season for discussions.

"The players understand the seriousness of concussions, and along with our consulting doctors we continue to discuss with them the importance of early diagnosis, treatment and proper recovery," NHLPA executive director Don Fehr said.

Detroit Red Wings forward Drew Miller said players choose to keep playing with head injuries for at least a few reasons.

"Guys downplay the symptoms or don't report them because of job security and they don't want to lose their spot," Miller said. "And, guys want to keep playing because they want help their team. In the back of our minds, too, you don't want other teams to know you have a head injury."

Retired players Dave Christian, Reed Larson and William Bennett filed a class-action suit nearly two months ago in federal court that alleged the league has promoted fighting and downplayed the risk of head injuries that come from it. They joined another group of former NHL players in the fight for compensation for head injuries they blame on a game that promotes hard-hitting action.

Current players seem to be adapting to the NHL's emphasis on safer play: Physical penalties -- such as illegal checks to the head, checks from behind and elbowing -- have dropped in each of the last six regular seasons.

An average of 1.03 physical penalties were called per game during the 2013-14 season, according to STATS, down from 1.14, 1.16, 1.25, 1.36 and 1.39 the previous five years. Suspensions have generally held steady at around 35 per season the past few years, and players are sometimes forced to sit even if no penalty is called.

Montreal's Brandon Prust wasn't penalized for a hit that broke the jaw of New York Rangers forward Derek Stepan during the Eastern Conference finals, but he was suspended for two games by the league. Stepan sat out one game after going through a series of tests.

"The protocol helps make sure that the player is OK and that he is not playing with something that he shouldn't be," he said. "I think it's a good step in the right direction."

Ultimately, though, players have to protect themselves and each other.

"It comes down to the guys on the ice respecting each other and playing it as safe as possible," Chicago Blackhawks forward Patrick Sharp said. "You see some of the big hits this year, inevitably you're going to catch a piece of the head and cause a problem, but the league's done well with suspensions and penalties and the players have done a good job as far as the respect factor."