UMPIRES in charge of Thursday night's Fremantle-Collingwood game would have stopped play after Lachie Schultz was concussed if they had been aware the Magpies forward was in trouble.

However, the AFL says the field umpires did not see Schultz's injury and allowed play to continue until Collingwood forward Jamie Elliott marked the ball in the forward line, about 15 seconds after Schultz was hurt. 

Schultz was concussed when he attempted to tackle Docker Jordan Clark in the centre of the ground early in the final term of the Pies' 14-point win over the Dockers at Optus Stadium.

Play continued with the Magpies winning the ball and eventually working the ball via Nick Daicos to Jamie Elliott, who marked in Collingwood's forward line.

However, the AFL said upon reviewing the game that the umpires could have stopped play when Daicos had possession just metres from Schultz, and before he kicked the ball to Elliott.

"The play can be stopped by the umpires, who are instructed to stop play as soon as they are aware there is an injured player in the vicinity of play. In last night's match the umpires did not see the injured player at the time, so play continued.

"Upon review, if umpires were aware, play would have been stopped when Daicos had possession in the middle of the ground."

Schultz struggled to rise to his feet and was eventually helped from the field by doctors, but Collingwood coach Craig McRae said after the game that "ideally" play should have been stopped, allowing medicos to assist Schultz sooner.

"We're all sort of just worried about his welfare and we called for the stretcher and the doctors were trying everything they can to just get Lachie OK and he sort of just jumped to his feet because it's just the way he goes, he gets knocked down and he gets up at every contest so we did what we could, but ideally you can stop the game," he said.