According to court records, Matthews, 22, is being charged with disruptive behavior or fighting. He has a pretrial conference scheduled for Wednesday morning. The summons was issued July 23.
Matthews spoke to reporters Wednesday morning, saying, "It's not something that any of us wish we were talking about today, but unfortunately it's the situation we're in. I regret any of my actions that put a distraction on the team or distress on any individual. I take a lot of pride in preparing myself for the season and representing the Toronto Maple Leafs as well as I can."
He said he couldn't make any further comments.
In a statement released Tuesday, the team said: "The Toronto Maple Leafs are aware of the complaint of disturbing the peace against forward Auston Matthews. Auston is cooperating fully with the relevant authorities, but neither he nor the Club will comment any further out of respect for the process involved."
According to the police report obtained by ESPN, the incident occurred May 26 at 2 a.m. local time. A female security guard was sitting inside her car outside the condo building where Matthews lives when she was disturbed by the sound of someone trying to open her door. She allegedly got out of her car and confronted Matthews, who she said was intoxicated.
As Matthews walked away, he "pulled his pants down, bent over and grabbed his butt cheeks," though he kept on his underwear, the woman told police.
Matthews signed a five-year, $58.17 million contract extension with the Maple Leafs in February. He was the top draft pick of Toronto in 2016, becoming the seventh American to be drafted No. 1 overall. He was born in California and raised in Arizona.