MELBOURNE is sweating on the fitness of small forward Jeff Garlett and could turn to silky half-back Christian Salem as the team prepares for a must-win clash against cross-town rival Carlton.

Having won its past three games, Melbourne remains a slim chance to feature in September for the first time since 2006.

If the ninth-placed Demons are to play finals, they must win their remaining two games against the Blues and Geelong and hope eighth-placed North Melbourne drops games to the Sydney Swans and Greater Western Sydney.

The Demons are two games and four per cent behind the Roos on the ladder heading into the final two rounds.

Garlett, who came down with a skin infection over the weekend, will have to get through training on Friday to prove his fitness for the game against his former side.

"He got a cut on his leg and it got infected on Sunday morning. The doctors jumped all over that pretty quickly with antibiotics,” Roos said.

"We'll pick him and we expect him to play, but we'll need to see him train on Friday to make sure he's OK."

Young forward Sam Weideman will also be monitored carefully after missing last week's game against Hawthorn with a corked quad, and is no certainty to return against the Blues.

"He was still getting a bit of soreness over the weekend so there's still a bit of a concern over his leg," Roos said.

"The doctors are still looking at all the different avenues. There's nothing too sinister, but he's a young player so we'll have a bit more of an idea at the end of training today (Wednesday) and we'll assess it after that."

Salem, after picking up 21 disposals and kicking two goals for the Casey Scorpions at the weekend, is a chance to be recalled having recovered from a thyroid illness.

"There'll be some tough decisions but Christian's someone you'd love to get back in because we know he's a quality player but it'll be based on form and who we can push in and out," Roos said.

Veteran defender Heritier Lumumba's season is over with the Demons deciding not to risk him after two concussion incidents, his latest coming at the start of July.

"He looks like he'll go on the long-term injury list. We don't expect him to play this year," Roos said.

"It's an industry wide issue. We've seen players this year who have had a lot of time off and we've seen players ruled out of games a lot quicker than in the past.

"We're just hoping H gets right and comes back to pre-season and has a good year next year."

Roos said it was an exciting time for the club and players were "bouncing into work and looking forward to training".

"Having been involved in teams that can't make the finals, sometimes you can lose a bit of interest.

"At this stage the players are really interested but, as I said, Carlton beat us last year and we know we're going to have to play well to beat them.

"Everyone knows what the ladder looks like. The players give me some stick about it sometimes, but I always tell them there's a bloke in the scoreboard and there's also a bloke at the AFL who looks after the ladder.

"We don't have much to do with that and we can't manipulate it. That's really the message to the players."