Yesterday, an Auckland Football Federation judicial panel held a hearing regarding the incident.
After reviewing the reports from the day and hearing a submission from Fasavalu's legal advisers, the panel imposed an indefinite suspension from all involvement in the game.
The suspension can be lifted only by application to the board of New Zealand Football after a minimum of 12 months.
Fasavalu was also fined $1000.
The player and club have 14 days if they want to appeal against the findings.
Auckland Football Federation chief executive David Parker said the judicial process under Auckland Football and New Zealand Football regulations had been fully tested by the assault.
"What this type of incident shows is that we have the processes in place to respond in an appropriate and timely manner and at the same time have the ability to support our volunteers."
As part of his bail conditions from Manukau District Court, Fasavalu has had to surrender his passport and reside at a Mangere address. He is due to reappear this month.
Yesterday, Manukau City chairman Saubree Edinberry apologised to Mr Gattsche and his family on behalf of the club for what happened.
"We'd also like to apologise to the Auckland Football Federation and the soccer fraternity for the incident.
"The incident was isolated and totally out of control. We, as a club, had absolutely no control to stop the incident from happening - it happened on the field and it happened so fast.
"We'd also like to apologise to our fans who come out and watch us play."
Manukau City had been painted in a negative light because of the incident and Mr Edinberry said the club was keen to distance itself from Fasavalu.
"We don't expect that [behaviour] to happen in any form or way.
"A player of any club, for that matter, shouldn't ever lift a hand towards a player or towards a referee," Mr Edinberry said.
"It was one player who lost the plot with the referee and I don't think the club should be dragged down in that negative way."
Mr Edinberry said the club wanted to promote soccer in a positive light and the sport had lost out because of the incident.
He said Manukau City intended to have its players attend referees' meetings so they could gain a better understanding of where the match officials were coming from when they gave penalties on the field.