MELBOURNE'S key forward stocks have been severely weakened after scans revealed Chris Dawes will miss up to a month with a calf strain.

Dawes injured his troublesome calf at training on Tuesday, leaving him in doubt for the opening rounds of the season.

The latest calf strain adds to a frustrating pre-season for the 27-year-old. who had already been on a modified program since Christmas.

"Chris has struggled to have a consistent block of training this pre-season," Demons football manager Josh Mahoney told

"He had only just returned to main training on Tuesday when he hurt his calf.

"Scans have revealed a strain which he will now start to rehab, and we hope for no further hiccups from here in the build up to his return."

Dawes has had a history of calf issues and managed just 14 games in 2015, with an ankle problem also causing some bother towards the end of the season.

Given his soft-tissue issues, Dawes even sought advice from specialists at the Australian Institute of Sport in 2014. 

With Dawes' availability for the start of the season up in the air, Sam Frost and Cameron Pedersen look the most likely candidates to take the second tall forward slot alongside Jesse Hogan.

Frost, who played only the first three games of the season at Melbourne last year before being sidelined with a long-term toe injury, was playing in that role in Tuesday's match simulation.

Pedersen has played in a multitude of spots, including forward, in his three seasons at Melbourne and can also pinch-hit in the ruck if required.

Sam Weideman, the young forward the Demons drafted with pick No.9 in last year's NAB AFL Draft, has been cautiously managed this pre-season after persistent ankle injuries in the final year of his junior career.

The 18-year-old is considered a very raw prospect and a long-term investment for the club.

He has been working closely on his marking technique and forward line craft with development and rehab coach Daniel Cross in the past few weeks.