EMERGING Melbourne star Christian Petracca was on light duties at training on Friday after experiencing some soreness, but the club is confident he will be able to rejoin the main group next week.

Co-captain Nathan Jones was another to be on a modified training program at Gosch's Paddock, and he left the training track early after completing his running and skills component.

He will be monitored closely next week after experiencing some back spasms, but the Demons expect he will also be able to join in full training later next week or early the week after.

Petracca was on a reduced training load and joined key forwards Sam Weideman and Tim Smith for repeat running efforts around the outside of Gosch's Paddock.

Petracca has been training with the midfielders this pre-season and his improved endurance was noticeable as he, Weideman and Smith completed a series of repeat 200m and 300m efforts.

The 22-year-old averaged 18.8 disposals and one goal from his 22 matches in 2017 and the expectation is that he will take another step forward this year.

Christian Salem, Tom McDonald and Corey Maynard were the standouts as the main group went head-to-head in a nine-versus-nine match simulation hit-out.

Salem is in top physical condition after a strong pre-season and it showed as he covered the ground as well as he ever has.

His clean skills and ability to put teammates in better positions made him one of the key performers, and the Demons are hopeful he is over the injury and health concerns of the past couple of seasons.

After spending much of the pre-Christmas training block in rehab following surgery on both of his ankles at the end of last season, Tom McDonald is back in full training and was in fine form on Friday.

McDonald had a real presence up forward and even shoved teammate Josh Wagner out of the way and on to the ground in a marking contest that led to a goal for his side, demonstrating his brute strength.

The Demons expect McDonald to line-up alongside Jesse Hogan in a potent forward line which will also contain Jeff Garlett, who is back with the main group after a rib injury limited him early in the pre-season.

Mature-age rookie Corey Maynard continues to go from strength to strength and shapes as a player in contention for a round-one berth.

The 26-year-old made his debut against Greater Western Sydney in round 20 in his only match for the season, but averaged 23.8 disposals from his 16 games in his maiden season for the Casey Demons in the VFL. 

Maynard's game sense came to the fore in a couple of ways on Friday.

First, when he froze a teammate with a baulk to create space for himself in congestion, and second, when he put his body on the line for a crucial spoil that ended with his side taking the ball up the other end of the ground and scoring.

Marquee recruit Jake Lever looked poised and polished in his defensive post, with fellow backmen Oscar McDonald, nominated by coach Simon Goodwin as one of his standouts of this pre-season, and Sam Frost also combining well together.

The players finished the session with a gruelling 400m, 300m, 200m, 100m running pyramid (with only a one-minute-and-15-second break between reps), with Alex Neal-Bullen and Tom Bugg the shining lights in the running component of training.

The Demons kick off their AFLX campaign at Etihad Stadium on February 16.