The charge is in connection with an incident that occurred Oct. 30 in Denver.
Varlamov was arrested for allegedly assaulting his girlfriend. He turned himself into police that evening and spent the night in jail.
"We are aware of the decision made by the Denver District Attorney's Office today to pursue misdemeanor assault charges against Avalanche Player Semyon Varlamov," the NHL said in a statement. "While we will continue to monitor the situation, we do not expect to take any action or have any further comment pending the resolution of those charges."
"The Colorado Avalanche organization was informed about today's decision from the Denver District Attorney's Office and will have no further comment until the entire legal process has concluded," the Avalanche said in a statement.
Varlamov had an initial court appearance Oct. 31 and was released on $5,000 bond and given permission to travel with the team. He was ordered to stay away from his girlfriend and to not have contact with her.
Varlamov is due back in court Dec. 2. He was charged by Denver District Attorney Mitch Morrissey.