"This issue didn't affect his signing and his contract at the club. We showed it while [we] proudly introduced him to the Italian press in a press conference held in August.
"I personally spoke to the player Tuesday when he returned back in Parma. Mils is very focused on returning to the field as he sustained a muscle strain prior to the game on October 4."
Mr Mussini said Muliaina was a "great professional" who was supported by the club.
"We've also appreciated while it has been a tough time for him, he has still promoted the game of rugby in many community events with a positive approach to all the club partners, supporters and younger players of the franchise.
"We're all looking forward to Mils' debut game. We know he'll be a key player for us thanks to his huge experience and his strong aim to be important for the club."
Earlier this week Muliaina thanked the club, family, friends and even strangers for supporting him. He also said he felt "aggrieved" by his treatment.
"Not being able to comment publicly has been very frustrating. While I understand the police have a job to do, the manner in which I was arrested I find difficult to understand.
"I can still hold my head up high and, as the judge said, this is no stain on my character."
His lawyer, John Charles Rees, QC, said the decision to prosecute Muliaina was "outrageous", while Muliaina's New Zealand-based agent Simon Porter and New Zealand Rugby Players' Association chief executive Rob Nichol added their voices to criticism of how the rugby star was arrested.
"It was simply unnecessary to drag him off a rugby pitch under intense global media scrutiny. Unfortunately, it was a demonstration of police grandstanding at its worst," Mr Porter said.
Muliaina played for the All Blacks between 2003 and 2011 and has since had stints in club rugby in Japan and Ireland.
