Police have appealed the discharge without conviction of Losi Filipo.
Filipo, 18, was last month discharged without conviction for an attack that occurred in central Wellington in October 2015.
He was charged with assaulting Kelsey Odell, 22, her boyfriend Hayden Williams, 22, Greg Morgan, 21, and Olivia Samuels, 22.
The sentence caused an outcry from Filipo's victims and other members of the public, who say Filipo should be convicted.
In a media statement, the Crown Law Office said the Solicitor-General had reviewed the matter.
"Approval has been given to the Police to file an application for leave to appeal, on a question of law, against the decision to discharge Mr Filipo without conviction.
"That application has now been filed in the Wellington High Court."
The Wellington and New Zealand Rugby Unions are refusing to comment over the Solicitor-General's decision.
New Zealand Rugby spokesman Mike Jaspers said the union would be making no further comment on the teenage player's situation at this stage.
A Wellington Rugby Union spokesman echoed that stance.
"We cannot comment as this matter is now before the courts," he said.
The New Zealand Rugby Players Association said it had no immediate comment on the Solicitor-General's actions but may release a statement later.
Dr Bill Hodge, Associate Professor of Law at the University of Auckland and who was among those critical of Filipo's discharge, said the Solicitor-General had acted to ensure the law was applied evenly and appropriately.
While Police had lodged the application, it would be a lawyer from Crown Law that would argue the case, he said.
"The argument will be that the judge didn't take into account the appropriate sentencing principles - not that on the facts he got it wrong. It's about sentencing principles," Hodge said.
"In my view it isn't [a response to the outcry] it's a response to the need to ensure that people have confidence that the law is applied in the same way in all the courts up and down the country."
Hodge today looked over another case where the High Court accepted an appeal against a discharge without conviction in Auckland.
That was done because the judge wrongly took into account considerations about deportation.
Hodge said he did not know all the detail of the Filipo case. But the argument often heard in similar cases that a conviction would prevent a person travelling as part of a job as a professional athlete was misleading.
"It is improper for a judge to say, 'Another authority may take action because of my decision.'"
The confirmation of an appeal was immediately applauded by Bob McCoskrie, director of the conservative lobby group Family First NZ.
"This offender-friendly sentence sent a dangerous message that we don't value the protection of victims and the safety of the public in a case that involved significant violence towards both males and females," he said.
"This is not about revenge as some will suggest. This is about an appropriate sentence which reflects the gravity of the crime."
Wellington Rugby terminated Filipo's contract earlier this week.
Members of the public are reacting on social media, following the news.
Many are praising the move by police to appeal Judge Bruce Davidson's decision.
One person simply wrote: "Finally!"
Another said: "About bloody time and it better not be a smack with a wet bus ticket!"
Another person commented that their faith in the New Zealand justice system - and humanity - had been restored following the news.
Others, however, are questioning the motives to seek an appeal.
One man wrote: "What a joke. Only reason police are doing anything is because of the public outrage.''