The 32-year-old played 43 games for Otago as hooker and in 2010 was included in the wider training squad of the Highlanders.
Mirrielees, a business owner, was drinking with team mates in the early hours of July 19, following a rugby game, when the assault occurred.
A woman, who had an association with the team, was also socialising with them.
"As the victim was standing with the group, the defendant came up behind her and he grabbed her on the buttocks,'' a police summary of facts said.
"When she turned around and saw the defendant standing there, she pushed him away; he reacted by grabbing the collar of her jacket and raised his other arm.''
Other team members intervened and separated the pair.
Mirrielees, when spoken to by police, declined to comment or offer an explanation for his actions.
Defence counsel Anne Stevens said, during sentencing yesterday, that the offending occurred in a "grossly intoxicated environment''.
"Everybody in the bar seemed to be intoxicated and it seemed to be throbbing with people,'' she said.
Mirrielees had taken steps to address his drinking and removed himself from the rugby team.
He pleaded guilty in the Dunedin District Court to one count of Summary Offences Act assault on October 29.
He sought final name suppression on the grounds he would suffer extreme hardship through loss of business, but Judge Michael Turner quashed that bid yesterday.
Mirrielees' suppression ended at 10am today.
"[The offending has] got sexual connotations, so why shouldn't people who want to go to this business know he's grabbed somebody's bottom,'' Judge Turner said.
Defence counsel Anne Stevens confirmed this morning Mirrielees would not appeal the decision.
Mirrielees was sentenced to 60 hours community work and ordered to make a $500 emotional harm reparation.
Details of the victim, the rugby team and Mirrielees' business were suppressed.
