After seeing star goalie Carey Price bowled over in the crease a few times in recent games, Therrien said it is time for better protection.
"It has to stop," said Therrien. "It's not normal that players let themselves fall into the goalie like that. Those players never fall into the boards that way, but they're able to fall into a goalie and risk causing an injury."
Most recently, Price was knocked down by Patrick Kaleta in a loss to Buffalo and by Troy Brouwer in a win over Washington. Price was knocked out of the Eastern Conference final with an injury last spring after a collision with Chris Kreider of the New York Rangers.
Therrien said there is little referees can do to stop the hits because the most they can call is two minutes for interference. And having players retaliate against the aggressor creates a penalty risk.
He said running goalies has become common around the NHL.
"Even if you have a defenceman who is six foot six, 250 pounds, if you lose position and the player on the offensive side lets himself go into the goalie, there's nothing you can do," he said. "I'm not only talking about Carey Price, I'm talking about goalies in the NHL. We have to find a way to protect them."
Price said the league's crackdown on obstruction that followed the 2004-05 lockout makes it difficult for defencemen to hold up forwards intent on crashing the net. He said being run into is something goalies learn to live with.
"That's what (the NHL) wanted and that's the problem they created," Price said. "I know what my job is, to stop pucks.
"I don't expect anybody to retaliate for me, either. I'm a pretty big guy. I can take care of myself. It's part of the game now. Hockey's a physical game now. I don't know what else to say about it."
Price, who posted consecutive shutouts last week, will be in goal when the Canadiens play host to the New Jersey Devils on Saturday night. Therrien has yet to decide on his goalie for Sunday night's game in Boston against the rival Bruins.
Defenceman P.K. Subban was fined US$2,000 this week for a second embellishment offence. The call was made during a 1-0 win over the Rangers when Subban went down after a shove from behind by Kreider.
He had been warned for embellishment during a Jan. 6 game against Tampa Bay. Therrien wasn't pleased with those calls.
"We encourage our players to play the right way and play a demanding game," said Therrien. "Honestly, I don't agree with the calls. It comes down to referees making a judgement. There were a few occasions I did not agree."
Subban said the fine won't affect his game. He is not concerned that officials may watch him more closely for diving because he is a repeat offender.
"When I play the game, I don't think about being on anyone's radar," he said. "I'm just playing the game hard, trying to help my team win any way I can.
"The league's too good, the players are too good and the games are too tight to be thinking about anything else. At the end of the day, that's the decision that was made and I'm going to respect the decision and move on down the road."
There is a possibility that Boston, which will also be playing a second game in as many nights, will start backup goalie Malcolm Subban — P.K.'s younger brother — in goal.
"If he is playing, it will be a special night," he said.