MELBOURNE defender Steven May is set to be sidelined for up to a month, having suffered a fractured right eye socket and a concussion as a result of a gruesome collision during Sunday's victory over Geelong.

May was taken straight to hospital after catching a stray elbow from Cats spearhead Tom Hawkins, which left the in-form defender with blood streaming from his eye region and with significant swelling in the area.

He was discharged from hospital on Sunday evening and posted about the "freak accident" on social media on Monday, with the Demons expecting the star backman to miss anywhere between two to four weeks.

>> WATCH THE INCIDENT IN THE PLAYER BELOW

May will also enter the AFL's new 12-day concussion protocols, meaning he is at least likely to be absent for the side's upcoming two fixtures against Hawthorn and reigning premiers Richmond.

Melbourne, who is one of only three clubs to remain unbeaten throughout the season's opening four matches, then faces North Melbourne and fellow 4-0 team Sydney immediately afterwards.

Adam Tomlinson moved to Hawkins after May was substituted out of Sunday's 25-point victory, performing admirably and keeping the reigning Coleman Medal winner to just two goals.

But young defender Harrison Petty has been earmarked as May's likely replacement for this Sunday's upcoming clash against the Hawks, with coach Simon Goodwin categorically ruling out the possibility of Tom McDonald returning to a defensive post.

Key forward duo Ben Brown and Sam Weideman also featured in a VFL practice match on Saturday after overcoming knee and leg injuries respectively, with both likely to again feature for Casey this weekend as they continue their recoveries.