Unsealed NHL documents in the concussion lawsuit brought by former players reveal a snapshot of an internal debate by league officials over head injuries and a deeper concern about the impact of fighting than what had been publicly shared.

In some emails, among the 298 documents recently declassified in the case by U.S. Magistrate Judge Janie Mayeron, Commissioner Gary Bettman's tone comes across as defensive regarding criticism directed at the league for its handling of player safety and the fighting culture that has existed on the ice for decades.

Other exchanges, however, suggested an NHL leadership that's conflicted over a complicated issue.

In a January 2009 exchange between senior vice president Colin Campbell and Canadian TV broadcast reporter Bob McKenzie, Campbell said he might go public with a recommendation that the NHL get rid of fighting or at least attempt to reduce it.

In a September 2011 thread between Bettman and Brendan Shanahan, who succeeded Campbell as the league's disciplinarian, Bettman told Shanahan that his comments to CBC-TV revealing the league was scrutinizing fighting "went too far." Bettman called the situation "sensitive territory," citing the need to be "very careful."

The material was obtained by The Associated Press from counsel for the plaintiffs and first reported by Canadian sports network TSN.

More than 100 former NHL players have joined the class-action lawsuit against the league, alleging it had the resources to better prevent head trauma, failed to properly warn players of such risks and promoted violent play that led to their injuries.

The plaintiffs' primary request is medical monitoring for the roughly 4,800 living former players, plus additional unspecified relief. The 133-page master complaint is packed with anecdotes of former players suffering from a variety of neurodegenerative conditions they've tied to hits to the head they experienced on the ice.

Spokesman Frank Brown said Tuesday the league's stance has not changed from Bettman's comments from Jan. 30 during an All-Star game weekend news conference.

"The selective released leaking of documents out of context may cause some people to scratch their heads, a couple of other people maybe to for a brief moment be a little embarrassed about salty language or the like. But I'm very comfortable with our record," Bettman said then.

"I think in terms of us doing our business on an ongoing basis and the fact that we have the league to run, I'd prefer these things not be public. They'll be a distraction at best, but I don't think they impact the rest of the case."

The unsealed material showed a pattern of attention by the league to media coverage of concussions. In one email exchange with NBC Sports executive Sam Flood in March 2007, Bettman said he was annoyed over then-broadcaster Brett Hull criticizing the league for eliminating fighting.

The declassified documents also indicated an increased focus by NHL officials on concussions and fighting as early as 2004, following Vancouver's Todd Bertuzzi's vicious on-ice attack on Colorado's Steve Moore.

The league established what became its concussion subcommittee in 1997. It wasn't until 2010 when the league introduced Rule 48, outlawing illegal hits to the head.

More than 300,000 documents and 2.5 million pages were originally marked protected by the league, and Mayeron agreed with the plaintiffs that some should be public.

In the NHL's defense of keeping the material sealed, Campbell wrote that his "colorful, crusty and sometimes crude" language would be appreciated only by "hockey people" and would embarrass the league if revealed.

Campbell didn't pull many punches in the emails that were released.

In one November 2008 exchange with Bettman, Campbell criticized Toronto defenseman Mike Van Ryn for sustaining a concussion, broken nose and hand after being checked from behind and into the boards by Montreal's Tom Kostopoulos.

After calling Van Ryn "soft," Campbell suggested, perhaps sarcastically, that Van Ryn should be the one punished for putting himself in a bad position. Kostopoulos was issued a three-game suspension. Van Ryn missed a month and played just 13 more games that season. He later cited Kostopoulos' hit as the reason he retired.

In one message to then-Anaheim general manager Brian Burke about a December 2006 fight between Washington's Donald Brashear and Aaron Ward of the New York Rangers, Campbell called Brashear a "bully" and Ward a "punk."

In that same e-mail, Campbell referred to critics of the NHL's handling of safety issues as "tree huggers." He used the term "Greenpeace pukes" to express his disdain in a separate exchange with Burke in March 2007.

In his response to several league officials regarding a May 2013 proposal to the NHL's concussion working group from Ottawa head athletic therapist Gerry Townend, Campbell wrote simply, "This guy is a freaking idiot!"