(CNN) -- The body-checking incident that left a National Hockey League player with a concussion and fractured vertebrae has not only some fans concerned but also at least one corporate sponsor -- Air Canada fired off an open letter to NHL Commissioner Gary Bettman, threatening to yank its sponsorship of the league.
The letter, sent last Wednesday by Denis Vanda, director of marketing communication for the airline, expressed Air Canada's concern about recent violent checks. The letter said unless the league "takes immediate action with serious suspension to players to curtail these life-threatening injuries, Air Canada will withdraw its sponsorship of hockey."
Boston Bruins' Zdeno Chara slammed Montreal Canadiens' Max Pacioretty during last Tuesday's game, causing Pacioretty to fall to the ice. Pacioretty was taken from the ice on a stretcher and currently he is in a hospital. He is out indefinitely, according to Canadiens' coach Jacques Martin.
Chara received game penalties, but no fine or suspension. The NHL said it stands by its ruling that no suspension is warranted.
Veteran sportscaster Len Berman told CNN the controversy may not be over. "The commissioner has already said it's not going to affect anything, but I have to guarantee you that if sponsors stepped up and said, 'Hey we're going to be pulling out' that the NHL is going to listen."
The NHL's annual general managers meeting began Monday with attendees looking at the effects of the leagues' Rule 48, put into effect this season and banning purposeful checking of players' heads and from their blindsides, according to NHL.com.
During the meeting in Boca Raton, Florida, the NHL released data showing there has been a decrease in the incidences of concussions during the League's 2010-11 season. NHL.com says the data shows one blindside hit that has caused concussion this season, compared to four from the previous season.
For a lot of hockey fans, fights and hard hits are part of the lure of the game. Berman says fans enjoy watching the fights, "Next time you see a hockey fight, look at all the fans right behind the fight. They all have big smiles on their faces. You never hear booing at a hockey fight. You only hear cheering. "
Chara says the hit on Pacioretty wasn't intentional and he meant no harm. Yet, days later, Chara -- not known for dirty plays -- is still hearing booing from fans. "It doesn't bother me. It's just a part of the game. The fans are...they have the right to express their opinion....towards different players." Chara told CNN.
But do the sponsors have that right?
One player sees it both ways. Andrew McDonald, a New york Islanders' defenseman, said, "I can see their concern. They're obviously worried about player safety...I think as players, we appreciate that. But again, as players, we know what we're going into when we go into a hockey game."
CNN's Susan Candiotti, Ross Levitt and Laura Batchelor contributed to this report.