The incident occurred off the ball in the fourth quarter and will be reviewed by MRO Michael Christian.
If the act was deemed intentional, low impact and high contact, Walters would receive a one-match ban.
The silky forward has been in career-best form over the last month to shoot into Brownlow calculations. He impressed again against the Demons with a three-goal performance.
Fremantle host Carlton next Sunday at Optus Stadium.