Rugby union great Tim Horan and former schoolboy player Perry Cross have called for changes to school competitions after several students were seriously injured in matches in Queensland.

A 15-year-old schoolboy remains in intensive care after suffering serious neck injuries while playing on Saturday morning at Brisbane's Nudgee College.

Alexander Clark is the fourth student to sustain an injury while playing the sport in as many weeks.

He was rushed to Lady Cilento Children's Hospital and underwent successful surgery to stabilise his neck on Saturday night.

Nudgee College principal Peter Fullagar said in a statement today that Alexander's condition was stable and he remained in intensive care.

"He is communicating, alert and in remarkable spirits," Mr Fullagar said.

"While Alexander's recovery is underway with the support from his medical team, we are realistic this may be a long journey."

Mr Fullagar expressed on behalf of the Clark family appreciation for the support they had received over the past 48 hours.

"They have been comforted and strengthened by the Nudgee College community response, as well as the show of support extended by schools and representatives of all educational sectors," he said.

He said the college was liaising with Rugby Australia, Queensland Rugby Union, and the GPS Association.

"We will be fully supportive of any initiatives that review the safety of all rugby players," Mr Fullagar said.

"Mr and Mrs Clark have emphasised to me their support for the game of rugby, their empathy for the boys involved in the tackle, and their understanding that this was a tragic accident."

Two weeks ago, 16-year-old Gregory Terrace student Conor Tweedy suffered serious neck and spinal injuries during a scrum.

Call for certificate system for school-aged players

Former Wallaby and Spinal Life Australia ambassador Tim Horan has visited Conor and Toowoomba Grammar School student Ollie Bierhoff, as they recover from their injuries.

"[It's] distressing for the families involved," Horan said.

Student Conor Tweedy, with Tim Horan on left, suffered serious neck and spinal injuries during a scrum. ( Supplied: https://conortweedy.com/news-2/ )

He said he supported the introduction of a certificate system for school-aged players who pack down in the front row.

"Certificate 1 may be while you're at training, you're allowed to pack in the front row," Mr Horan said.

"Certificate II means that you can now compete in a game, because you understand how to pack, where to put your arms, where to put your shoulders, what happens if the scrum goes down, where does your head go."

The former Australian centre said it was important school-aged players continued to push in scrums.

"In schoolboy rugby, you are only allowed to push one-metre in a scrum," Horan said.

"You can't not push in the scrum, because when you finish at schoolboy level, you go into club land, and you are pushing in a scrum — so you've got to make sure there's a transition."

Seven-a-side option 'reduces the risk'

Perry Cross became a quadriplegic in 1994 while trialling for a Queensland representative rugby team as a 19-year-old.

Perry Cross says the recent spate of injuries is deeply worrying. ( ABC News: Tom Forbes )

Mr Cross now runs his own spinal research foundation and said the recent spate of injuries was deeply worrying.

"Rugby has had a wake-up call — the writing is on the wall — this is changing the lives of young boys, young kids, their families, their friends," Mr Cross said.

He said rugby union was a safe game when played properly, but he supported school-aged children playing the seven-a-side version.

"Seven-a-side reduces the risk, it's more running rugby, it opens up the game, less contact … it's a safer way forward," he said.

"If mums and dads don't like the risks of their kids playing 15-a-side, they go into other sports and rugby needs to face up to that."

Safety aspects of game have improved

However, former Wallabies head coach John 'Knuckles' Connolly said although the incidents were disturbing, he did not think there was a need for a full inquiry into rugby league at the school level.

Now a councillor on Sunshine Coast Council, he said safety aspects of the game had really improved since he played.

"It's always disturbing when you hear these things," Cr Connolly said.

"You've got to look at the hundreds of thousands of games of rugby league, rugby union, Australian rules and all contact sports that are played and try and isolate where the problem was.

"I think they have isolated in the past that it was the scrums in rugby — they've changed the laws dramatically to fix that."

Cr Connolly said "we've had a decade of a good run".

"All of a sudden we've had one bad one now from a scrum and another from someone diving over in a corner," he said.

"You don't want to overreact but equally you don't want to under-react to see if there's anything you can do.

"There will be reviews done of this to see if there's anything that can be done going forward.

Cr Connolly said his heart went out to the parents involved.

"It's shattering … and having a 14-year-old boy myself obviously you relate it to your situation, so it's always disturbing and upsetting when these things happen," Cr Connolly said.

"It's just a terrible accident, just like riding a bike."

Incidents involved GPS schools

Earlier in July, two students from Toowoomba Grammar school sustained similar neck injuries in separate incidents one day apart.

Both students underwent surgery and were released from intensive care.

All four incidents involved schools competing in the rugby union competition of the Great Public School Association of Queensland (GPS).

The GPS schools that are members of the association include: Anglican Church Grammar School, Brisbane Boys' College, Brisbane Grammar School, Brisbane State High School, St Joseph's College - Gregory Terrace, Ipswich Grammar School, St Joseph's Nudgee College, The Southport School and Toowoomba Grammar School.

GPS Assocation of Queensland executive officer Nicole L'Efevre said on Monday night everyone in the GPS community had been "deeply affected" by the recent spate of injuries.

"Each GPS school will contribute to a technical review of these recent incidents with Rugby Australia and Queensland Rugby Union tomorrow, as we continue to focus on safety as our very highest priority," she said.

Queensland Government Minister Kate Jones said it would only review the competition if there was demand from schools.

"I think that this is a discussion that has to happen firstly with schools sports amongst themselves and we'll of course listen to any action they would like us to take," she said.

"But I think what's paramount right now is that the care is given to ensure that this boy has a speedy recovery.