The Demons lost an astounding 17 straight games at Subiaco Oval between 2004 and 2016.

Eight of those losses were by 54 points or more but two straight wins out west have banished the curse.

Tom McDonald kicked a late goal to lift the Demons to a three-point win over West Coast at Subiaco Oval last year.

And five weeks ago, Melbourne broke their 12-year finals drought after securing a fighting 17-point win over West Coast at Optus Stadium.

Saturday's preliminary final at a sold-out Optus Stadium is shaping up to be an epic.

Travelling to Perth no longer holds any fears for the Demons and a third straight win out west would lift them into their first grand final since 2000.

But a deeper look into Melbourne's recent win over West Coast might raise some worries for the Demons.

West Coast were without Josh Kennedy in that match and Jack Darling lasted just 10 minutes before being ruled out with concussion.

Despite missing their two leading goal-scorers, West Coast held a slender lead in the final quarter before conceding the final three goals of the match.

West Coast are a perfect 11-0 with both Kennedy and Darling in the side this year and the pair loom as key figures in Saturday's sold-out clash.

Key defenders Oscar McDonald and Sam Frost are set to get the job on West Coast's star duo.

The Demons have the advantage in the ruck, with Max Gawn expected to dominate Eagles duo Scott Lycett and Nathan Vardy.

And Jack Viney's recent return from injury has given Melbourne extra star power through the midfield.

Both sides enter Saturday's match missing key figures.

Star West Coast trio Nic Naitanui (knee), Andrew Gaff (suspension) and Brad Sheppard (hamstring) will miss the rest of the season, while the Demons are without bookends Jake Lever (knee) and Jesse Hogan (foot).

The Demons will have to buck the odds to keep their fairytale alive, but at least recent history is on their side.

Australian Associated Press