Chris Rivett, the director of communications for the Professional Referee Organization, has backed Messi, saying the Argentine did not enter the locker room.
"After speaking with match officials, we can confirm he did not enter the premises," Rivett told ESPN.
Inter Miami boss Javier Mascherano, meanwhile, said after the match that he was unaware of the incident.
"No, no, no I didn't see anything," the coach said. "The truth is that the match finished and then I went into the locker room."