WEST Coast coach Adam Simpson insists any changes to the draft system need to be "foolproof" in a bid to avoid further controversy down the track.

Support is growing for a draft lottery to be introduced in a bid to remove the perception of tanking, with AFL greats such as Paul Roos and Michael Voss backing the move.

But Simpson doesn't want the AFL to rush into any decisions, saying it needs to take into account how any tweaks to the system might be exploited in the future.

"These things seem great in principle, and I like the idea of it," Simpson said.

"But we just need to make sure we get someone to 'what if' all these situations, because there'll be a way to expose something.

"Before we make change, let's just do due diligence and look at what the ripple will be, because there's always a ripple, and quite often there's ripples that we don't think of.

"Whatever it is, let's make sure we do the work behind it and it's foolproof, so we don't have to change it in two years."

West Coast will be aiming to snare their fourth straight win when they take on the sixth-placed Bulldogs at Etihad Stadium on Sunday.

The Bulldogs are the best defensive side in the league, conceding an average of just 68.5 points per game.

West Coast possess a talent-laden forward line capable of booting big scores.

But Simpson is well aware the likes of Josh Kennedy, Jack Darling, and Mark LeCras will have little influence if they fail to get much supply.

West Coast have developed a knack of producing champagne football during home games, but Simpson knows they'll need to get their hands dirty if they are to match it with the Bulldogs on enemy territory.

"Supply's important for us. In particular for the interstate games we've played this year, a lot of our numbers have been down," Simpson said.

"The cleaner, pure football that you see every now and then - and in particular when you've got dominance - it's hard to get against a match-hardened, finals-type team that we're going to confront this week.

Simpson and Bulldogs coach Luke Beveridge became good friends during their time together as Hawthorn assistants.

But communication has been cut off this week ahead of a game that could prove crucial to the top-four hopes of both clubs.