Melbourne defender Steven May is in doubt to feature in the Demons' Round 1 clash against Fremantle in 10 days time after suffering a concussion.

May sustained the head knock in his side's defeat to the Western Bulldogs on Monday and will now have to wait 12 days since the collision to be registered as fit to play for the Demons.

The 39-point loss sits exactly 12 days prior to Melbourne's clash with the Dockers at the MCG on Saturday, March 20, meaning May will be touch-and-go to play in the club's season opener.

“Steven was removed from play on Monday night and found to have mild concussion symptoms,” Demons' general manager of AFL performance Alan Richardson told Melbourne Media.

“Pleasingly though, on Tuesday morning Steven presented symptom-free and our medical team will continue to assess Steven each day in the lead up to our Round 1 match.

“We will ensure that every precaution is taken with Steven and a decision on his return to play date will be determined by his recovery.

“In line with the new concussion guidelines, Steven will undertake a graded return to training.”

North Melbourne midfielder Ben Cunnington is also under a concussion cloud having suffered a nasty head knock at training last month.

The 29-year-old copped an elbow to the head on February 12 and is yet to return to main training since the incident, per SEN's Sam Edmund.

The Kangaroos are set to face Port Adelaide on Sunday, March 21.