The GIANTS' spearhead, who has battled an ankle injury and a perforated eardrum in recent weeks, injured his arm when he was reported for rough conduct on Hawk Jarryd Roughead.
In the second term Cameron bumped Roughead, who was sliding into a contest. The GWS forward appeared to collect him with his left forearm before connecting with his hip, and was immediately reported.
Cameron received treatment for the injury on the interchange bench but returned with it strapped, and tried hard in the GIANTS' close defeat. He finished with a goal from seven disposals.
Coach Leon Cameron confirmed the star forward had left the MCG for further assessment after the defeat and said the club was unaware of the severity of the injury.
"It's a courageous effort from Jeremy to continue on playing. We don't know, he's off to hospital at the moment to find out whether he's got a broken arm," Cameron said post-game.
"He just continued to fight his way through it when it happened and I can't question his bravery. He's just a ball player, he has a crack, he puts himself in some really, really tough positions because he just wants to get the footy.
"But we're going to find out a little bit more as the night goes on."
Although it could have little impact if his injury is found to be severe, Cameron will also come under scrutiny from the Match Review Panel on Monday for the incident with Roughead.
His coach said the 21-year-old naturally hits the contest ferociously.
"If you watch him attack the footy, I can't have a crack at Jeremy for attacking the footy," Cameron said.
"It was Roughead and Jeremy going hell for leather at the footy, and the good thing is that 'Roughy' got up straight away. He's a tough player as well, but they're both ball players.
"I can't make a call on it until I actually have a look at the replay but…he's obviously been booked so we'll sort that out on Monday and Tuesday."
Despite the Cameron concerns there were plenty of positives in the GIANTS' defeat but, such was their dominance through the game, it will go down as one which got away.
The GIANTS skipped to an 11-point lead in the back stages of the third quarter before the Hawks overhauled that lead by the final change, but the young visitors kept challenging the Hawks until the dying moments.
Cameron said it was a game "we should have won" after completing a number of key tasks: compete for longer, winning the contested possessions, stopping the Hawks' uncontested marks and not letting them reach 400 possessions.
"Their effort and their energy was terrific from the very first bounce to the final siren. But we lost the game. We had an opportunity to win the game and we lost the game," he said.
"Good sides find a way, like Hawthorn, but I am confident the players will take out of that game the belief that they can compete for longer when their heads are in a really good space."
