MELBOURNE backman Christian Salem is set to miss up to four weeks with a hamstring injury suffered in the Demons' gritty three-point win against West Coast last Saturday night at Domain Stadium, ruckman Max Gawn says.

Salem, 21, finished the game on the bench and Gawn told reporters on Monday at the club that the prognosis didn't look good.

"From my understanding, (Salem) has done his hamstring," Gawn said.

"He looked pretty sore and he said he felt a grab so I'm presuming that will be your normal three-to-four-week type thing."

Jesse Hogan seems unlikely to face the Swans, with the key forward requiring more training after his testicular cancer surgery, while a hamstring concern means Jack Watts will be touch and go.

The fifth-placed Demons face Sydney on Friday night at the MCG. They have to contend with a third six-day break in a row, a challenge for Gawn himself.

Gawn returned against the Eagles after not having played since round three against Geelong, with a hamstring injury requiring surgery.

The 25-year-old started on the bench for a couple of quarters in a move to look after the big man.

"It (the return) was actually quite comfortable," Gawn said.

"I missed a couple of kicks but I'm probably not supposed to kick anyway.

"Apart from that, I felt pretty good. The six-day turnaround will test me. but I should be OK."

Gawn expected small forward Jeff Garlett (hamstring) to be fine to face the Swans and he doesn't expect courageous co-captain Jack Viney (shoulder) to be in any doubt either.

"He'll need his shoulder off the bone to miss a Friday night game," Gawn said.

Melbourne has been the AFL's form side and its comeback win, combined with similar efforts against Collingwood, Gold Coast, Adelaide and St Kilda have helped instill confidence.

"It comes from the young guys. Christian Petracca's a pretty happy and confident man and he gives nice belief to a lot of us," Gawn said.

"You have to play well to get belief as well, so getting four wins on the trot, including wins in Perth and Adelaide, gives you self-belief, and hopefully we can keep going."

He pointed to Leicester City's remarkable Premier League victory in 2015/16, as well as the Dogs' premiership last season, as parallels to Melbourne being in flag contention.

The Demons haven't won a Grand Final since 1964.

"There's stories of that happening at the moment. We touched on that a little bit, but any year can be our year," Gawn said.