Sunbury resident Danielle Desmond said the sentence was not enough.

"Nathan's life was taken in such a cruel and harmful way, I don't understand how the person responsible could be out walking around like the rest of us in as little as 17 years.

"I can't put into words how that makes me feel. Nathan was like a brother to me, always had such a smile on his face ... just such a genuine person who was always there when you needed him. A perfect example of a good true friend."

Nathan Smith, 19, pleaded guilty to murder, intentionally causing serious injury and affray over the attack on February 8 last year.

In the Supreme Court on Thursday, he was handed down a 22-year jail sentence and will serve a minimum of 17years before being eligible for parole.

He was among a group armed with machetes and baseball bats that killed Mr Roberts-Nunan, 20, and seriously injured his friend Stephen Thornycroft, lacerating his liver and spleen at a Diggers Rest football ground.

Eight other youths have pleaded not guilty to the murder and will face trial later this year.

The court heard Mr Roberts-Nunan had accompanied his younger brother Kyle to the football oval after the group had challenged Kyle to a fist-fight.

Sentencing Smith, Justice Paul Coghlan described the attack as "unremitting, senseless and cowardly mob violence at its most extreme".

He said Smith's decision to go armed to the football oval had led to catastrophic consequences, suggesting the case should be taught in schools as "an example of what a group of young men do in a group that they wouldn't do alone".

Smith took two boning knives to the football ground where he and eight other youths stabbed the 20-year-old to death.

The township of Diggers Rest is still reeling from the killing.

The devastated family of Nathan Roberts-Nunan, who was well-known in the area, left Diggers Rest not long after his murder.

Resident Aaron O'Connor remembers a "gentle giant" who had stood up for him when he was being bullied at primary school.

"He was probably in grade 6 and I was in grade 3, I had few issues at primary school and he stood up for

me."

Mr Roberts-Nunan played his junior football with Diggers Rest Junior Football Club, the Burras, where his father Phillip coached.