ANKLE surgery at the end of last season has led to a delayed start to pre-season training for promising young Melbourne forward Sam Weideman.

Meanwhile, key forward/defender Tom McDonald is set to join the main training group after Christmas following surgery on both of his ankles in September, while co-skipper Nathan Jones is back in full training after dealing with a niggling calf complaint.

Weideman, 20, went under the knife not long after the Casey Demons' semi-finals loss to Richmond in September and has not been spotted out on the training track since the first-to-fourth-year players began their summer campaign on November 6.

The young forward is nearing a return to the track, but the Demons will be cautious with his recovery, and a timeline for his return to main training is still up in the air.

"Weids had ankle surgery in the off-season, so he's progressing really well," Melbourne elite performance manager Dave Misson said.

"He's doing some good running on the 'AlterG' (Anti-Gravity) Treadmill and he'll start running outside next week."

The Demons are hopeful Weideman, whom they selected with pick No.9 in the 2015 NAB AFL Draft, will become a permanent fixture in the senior side in 2018 and provide a foil for star forward Jesse Hogan.

Weideman played seven games for the Demons in 2017, including the first four matches of the year.

The young key forward came back into the side for the first two games Jesse Hogan missed following his cancer diagnosis, but did not return to the team until round 21 when he played his last game for the year against St Kilda.

The 20-year-old kicked 14 goals in 14 VFL matches this season, including six (five in the first half) against Box Hill in a breakout individual performance.

McDonald, who is being pencilled in to play more as a permanent forward in 2018, has been progressing steadily in his rehabilitation following dual operations.

"[Tom's] done a lot of running and is starting to get into some pretty intense agility work, and football work," Misson said.

"He'll probably jump into the main group after Christmas, but he's going well."

Key defender Joel Smith is close to resuming training with the main squad after an injury-riddled year ended with him suffering a serious knee injury.

The youngster fractured his tibia while playing in the VFL in August, ruling him out for the rest of the year.

"Joel's towards the end of his rehab, with that fracture he had with his knee," Misson said.

"He's looking like the Joel Smith of old – really athletic and dynamic –so [we're] pretty pleased with how he's going."

Co-captain Jack Viney (foot) continues his rehabilitation indoors, Dean Kent (shoulder) is close to getting the tick of approval for some contact training and Tim Smith (navicular foot fracture) is back running.

Luckless midfielder Aaron vandenBerg is being monitored cautiously after he missed the entire 2017 season with a stress fracture in his foot.

"Vanders has been a little bit slow, just with that foot, but he's probably had his best week in rehab this week. We're really hopeful that he can start to progress a little bit quicker," Misson said.

Draftees Charlie Spargo, pick No.29, and Harrison Petty, No.37, have had a delayed start to their first pre-seasons at the club.

"Charlie had a shoulder reconstruction during the year and he's not far away from getting into some contact," Misson said.

"Ten days ago, Harrison fractured his elbow, tripping over a wire fence, so both of those guys have got a little bit of time in rehab."

Petty's injury was well-known at the Draft and the Demons had no hesitation in selecting him, confident the injury would only be a minor setback.