Ngor Aker, 17, whose family fled South Sudan many years ago, was rushed to hospital following the alleged incident on Saturday. He was part of a team from Geelong College taking on Haileybury College in an Associated Public Schools match. The match is now being investigated by both schools.

Ngor said the incident began when racist remarks were directed at him by an opposition player.

"A bloke turned around and said, 'watch out you've got a shadow following you', and I walked up to him and said, 'oi, trying to be racist?'" Ngor told Nine News. "And he's like 'yeah I am, what are you going to do?'"

Ngor told Nine News he pushed the other player, who then felled him. "I wasn't expecting it and then as soon as it happened I just got down on my knees and felt my mouth and saw a bunch of blood was coming out."

Witnesses said a Haileybury College player repeatedly hurled racist taunts at the Geelong College player before striking him as the third quarter drew to a close.

"It was a very strong strike on the jaw. It looked deliberate," one witness said.

"He fell to the ground and was quite shocked and there was blood coming from his mouth. You wouldn't expect that sort of incident to happen on a football field."

It's understood the teenager suffered a suspected fracture to the jaw, had five teeth knocked out and was in severe trauma. He was taken to hospital by ambulance shortly after the incident and spent the night in hospital.

“The resulting injuries appeared more like a traffic accident trauma than a schoolboy fight on a football field,” another man, who did not want to be named, said.

It's understood the Haileybury player was removed from the field following the alleged attack.

Staff and parents who watched the game said they were shocked by the incident.

"The fact that this kind of thing happens in schoolboy sport is incomprehensible," one man said.

Meanwhile, Ngor's mother, Chagai Gum Malong, told Nine News she was saddened by the incident.

"No one deserves to be put down because they were born in certain way. No one chooses that, it's painful," she said.

For his part, Ngor said he wanted to return to footy, but had misgivings.

"I want to go back and play but I'm just really scared it's going to happen again. No one deserves to be treated the way I was. It's 2018, we should be moving on from this," he told Nine News.

Geelong College principal Dr Peter Miller said the school community was shocked and saddened by the incident.

"A Year 11 student, Ngor Aker, suffered significant damage to his teeth when he was struck by an opponent in an incident behind play," he said.

"There is also an allegation of racial vilification by the other player directed at Ngor under investigation."

Dr Miller said the school had been in constant contact with the student's family and had offered support. He hopes Ngor makes a speedy recovery so the teenager can return to school as soon as possible.

The school is collecting information to assist with the investigation into the incident, which will be scrutinised at a tribunal later this week.

"The Geelong College does not condone and cannot accept violence or abuse of any kind, especially racial vilification," Dr Miller said.

Haileybury College principal Derek Scott said the incident was being investigated by the school and he could not provide further comment.

It's understood that video footage of the incident will be examined as part of the investigation.

With Larissa Ham