CARLTON is preparing for Charlie Curnow to make his long-awaited return to football through the VFL this weekend, though veteran Marc Murphy remains in doubt as his race to make game No.300 grows all the more uncertain.

Curnow, one of the club's and the competition's brightest young stars, hasn't played at any level for well over two years after suffering a series of debilitating knee injuries and further complications dating back to June 2019.

However, having returned to full training a month ago, the athletic forward completed his most vigorous session yet last Thursday and is subsequently on track to feature for Carlton's VFL team against Collingwood.

Curnow will now just need to make it through the club's next two main training sessions, set to be held on Tuesday and Thursday this week, in order to be given the green light to play next weekend.

It follows a carefully managed approach to his most recent setback, a stress injury to the patella of his right knee sustained last November, with the Blues still hopeful of the precociously talented 24-year-old making his AFL return later this season.

Curnow, who has also dealt with medial ligament damage, a dislocation, a fracture and a hairline stress response to his right knee since he last featured for Carlton, is expected to be on heavily limited minutes should he feature at reserves level this weekend.

However, the news is less positive for Murphy, who is unlikely to return from a minor calf injury for this Sunday's clash against old rivals Collingwood as the veteran midfielder's race to the 300-game milestone continues.

Murphy, who is currently stranded on 296 games with just six weeks remaining in the season, had initially been tipped to miss only a fortnight with a calf complaint but has not yet returned to training.

The Blues do expect ruck-forward Levi Casboult to return from knee swelling for this weekend's fixture against the Magpies, though defender Liam Jones remains in doubt due to a lower back injury.

Casboult's likely return should bolster a Carlton outfit that has had its key position stocks severely depleted recently, with Curnow (knee), Caleb Marchbank (knee), Oscar McDonald (back), Mitch McGovern (hamstring) and Marc Pittonet (ankle) all sidelined.

McGovern and McDonald are edging closer to returns over the next fortnight, while NAB AFL Mid-Season Rookie Draft selection Alex Mirkov could feature at VFL level this weekend following a knee injury.