MELBOURNE has no long-term concerns over star Christian Petracca's recovery from knee surgery, despite the midfielder/forward experiencing soreness and leaving the track early on Thursday morning.

The Demons will also monitor recruit Kade Kolodjsashnij, who sat out the last part of the near three-hour session, with the former Sun hoping to get over some tightness in his adductor.

Melbourne may back off Petracca's training load over the coming weeks as a result of the flare-up to ensure he has the best possible preparation for the 2019 season.

Petracca joined in the first part of full training and looked explosive and nimble after graduating out of the rehab group earlier in the week.

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But as the session went on it became clear that he had some discomfort around his left knee, which was heavily strapped following an arthroscope, and he sought some treatment from the club's medical staff.

After the discussion with the medicos and having completed a couple of mobility exercises to test the knee, the decision was made for Petracca to wrap up the session early.

Melbourne is confident the setback won't keep Petracca out of training for too long, while Kolodjashnij's program may be slightly managed.

Young Demon Bayley Fritsch was the standout player on the track on Thursday, playing a notable role mopping up across half-back and getting forward to deliver the ball inside forward 50 during match simulation.

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Fritsch, who played 23 games in his first season in 2018, has vastly improved his running capacity this pre-season, while his kicking was precise and he took a lovely mark coasting in from the side of the pack.

Aaron vandenBerg, who also joined full training early this week after overcoming a shoulder complaint, set the tone with his aggressiveness in the contest and his tackling pressure.

The hard-nosed forward was also particularly vocal throughout the session, offering encouragement to teammates Steven May and Alex Neal-Bullen at one stage for a defensive play they made.

May was another notable performer in match practice, standing tall in defence and using the ball with dare through the middle of the ground, while Christian Salem's foot skills were on-point throughout the session.

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The Demons trialled having Max Gawn in attack and recruit Braydon Preuss in the ruck as they determine the best ruck/forward combination for the 2019 season.

Gawn's height and power up forward yielded a couple of strong grabs up forward, including one where he stretched out in front of Sam Frost, while Preuss was also able to take some marks around the ground.

At one stage, Melbourne's forward line consisted of Gawn, Sam Weideman, Tom McDonald and Joel Smith (with one of the players rotating out), which shapes as a possible structure going into 2019.

Despite giving away plenty of height and weight, draftee Toby Bedford earned praise for a holding-the-ball tackle on Gawn that led to a goal.

The players finished the session with a taxing conditioning block full of grappling, shuttle runs and timed laps.

Melbourne's players will now have four days off, under the mandatory AFLPA break, before travelling to Maroochydore next Tuesday for a week-long camp on Queensland's Sunshine Coast.