Paul Bissonnette of the Pittsburgh Penguins and Dan LaCouture (R) of the Carolina Hurricanes exchange punches during a first period fight on October 23, 2008 at Mellon Arena in Pittsburgh, Pennsylvania Jamie Sabau/Getty/AFP/File The National Hockey League was hit Thursday with a second concussion-related lawsuit, as nine former players accused the NHL of failing to warn them of the dangers of head trauma.

The class action suit brought in a US federal court in New York could increase the pressure on the league, which was sued in November by 10 former players who said the NHL knew or should have known that repeated head blows can injure the brain.

The NHL has tried to reduce the number of blows to the head in recent seasons, banning deliberate hits to the head in 2011, although some former players claim it was too little and too late to help them.

The nine ex-players who launched the suit filed on Thursday include Dan LaCouture, who played 348 NHL games between 1998 and 2009, including spells with Edmonton and Pittsburgh.

According to the suit, LaCouture suffered a concussion in a brawl and still battles headaches, extreme irritability, sensitivity to light and depression.

Dan Keczmer, Jack Carlson, Richard Brennan, Brad Maxwell, Michael Peluso, Tom Younghans, Allan Rourke and Scott Bailey are also named as plaintiffs in the suit.

The suit alleges that the NHL, unlike other elite level organizations such as European leagues, "fostered and promoted an extremely physical game of ice hockey".

Having packaged and promoted a violent product, the NHL "has failed and continues to fail to warn its players of these risks and consequences of head trauma, concealing material scientific and anecdotal information from its players," the plaintiffs contend.

"Specifically, despite the fact that the NHL's violent game design induces head trauma, including concussions, the NHL has failed and continues to fail to warn its players of the risks to their lives and the devastating and long-term negative health effects," the complaint says.

The suit -- filed in US District Court, in the Southern District of New York -- however raised eyebrows because of a number of errors in the filing -- including the statement that hockey icon Gordie Howe died in 2009 of a degenerative brain disease.

In fact, it was the now 86-year-old Howe's wife, Colleen, who died of Pick's disease, a progressive form of dementia.

Among other errors, current Pittsburgh Penguins star Sidney Crosby's first name is misspelled -- it's written as "Sydney".