"(Zadorov's) leg went up and he used his upper body to flip him, and to me, that's a dirty hit," Julien said, according to Sportsnet.
"I don't know how the league is going to see it, that's up to them to look at it. But when I talk to our people, to upper management and all that stuff, we seem to think that's definitely a suspendable move on his part ... it's a dangerous play.
Julien also confirmed Kotkaniemi will not travel with the Canadiens when they visit the New York Rangers on Friday.
Kotkaniemi has already lost seven games to injury this season and has struggled to find his offensive touch. The 19-year-old has accrued just three goals and five points through 22 contests after a 34-point rookie campaign in 2018-19.