The NHL fined Prust US$5,000 on Tuesday, hours after he apologized publicly for his comments.
"Brandon Prust's post-game comments were both baseless and demeaning of a referee whose 20-year career in the league has been marked by professionalism, integrity and a high degree of respect from players, coaches and management," Colin Campbell, the NHL's senior executive vice-president, said in a statement.
Prust said after Montreal's 6-2 loss to the Tampa Bay Lightning on Sunday night Watson insulted him and swore at him. Following Tuesday's practice at Amalie Arena, Prust expressed remorse for revealing their on-ice interaction.
"I'd like to apologize to Brad Watson and the rest of the officials in the NHL," Prust said. "It was uncalled for.
"We got in a heated exchange and that should have stayed between us. I've always played by the code on and off the ice, I'm a pretty honest player. On Sunday I crossed the line."
Prust said he was agitated and emotional after getting into a fight late in the blowout loss.
"We got heated and I should know more than anybody what happens out there stays out there and there's a code and there's an honour," Prust said. "After the game I was not myself.
"I was fired up, I was out of my mind. If I could do it all over again, I probably wouldn't have even of went in to do interviews. But what's done is done, and we move on."
Prust said he was expecting to speak with Campbell on Tuesday but added he didn't reach out to Watson directly.
The 31-year-old hopes there's no fallout with the officials in Game 3 on Wednesday or later in the series because of his comments. Coach Michel Therrien said in French he wasn't worried about that because "the refs are professionals."
Defenceman P.K. Subban also isn't concerned about Prust's comments having a negative affect on the Habs moving forward.
"That's the integrity of the game," Subban said. "There's so many cameras, there's so many people with opinions, there's so many people watching, that's not going to happen.
"The game's going to be called fair."
Therrien met with Prust on Tuesday morning and was glad to hear of the public apology.
"Brandon Prust is a good person," Therrien said. "He's a guy that wants to win.
"Losing hurts him. He reacts with emotion. He apologized today, which I think was the right thing to do. But it doesn't take away from the fact that he's a good competitor."
Prust acknowledged a history with Watson that boiled over Sunday night. It was not immediately clear if Watson will work Game 3, but Prust will be back on the ice and understands what he has to do better than Game 2, when he racked up 31 penalty minutes.
"I have to learn to be better that way and keep my emotions in check because it's not really helping anybody," Prust said. "It's definitely not helping me or my team."
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