MELBOURNE defender Josh Wagner will miss the next month after fracturing his thumb in a VFL practice match on the weekend.

The 22-year-old, who was upgraded from the rookie list last year, suffered a dislocation in his second practice game of the year and will have an operation on Wednesday.

Wagner had already missed a large part of the pre-season with a fractured fibula.

The news is better for former Bomber Michael Hibberd, who is set to play in the VFL for the Casey Demons on Easter Monday.

"We expect him to play some pretty decent minutes on Easter Monday and if he plays well, he may put himself in the frame [for round five]," said Melbourne elite performance manager Dave Misson of Hibberd.

Ruckman Max Gawn had hamstring surgery on Tuesday and will be off his feet for a few weeks.

"He won’t do a lot for the first couple of weeks, but it’s an injury and a surgery that has occurred a lot in the AFL, probably in the last five years, so we’ve got a pretty good handle on the rehab requirements," Misson said.

"We’re hoping that it is only going to be 12 to 14 weeks."