GREATER Western Sydney is open to playing another opponent if Essendon doesn't field a competitive side for their NAB Challenge clash on March 13, coach Leon Cameron says.

The estimated 17 or 18 Bombers players served with infraction notices have confirmed they will not seek to have their provisional suspensions lifted to play in the pre-season competition.

It means top-up players from state leagues could fill in for the Bombers' matches against St Kilda on March 7, GWS and Melbourne on March 20.

GWS has closely monitored the situation and will contact the AFL later this week before it considers any contingency plans.

But Cameron said the Giants are worried they won't get a genuine contest against a cobbled together Essendon team.

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"That's the concern that we face," Cameron told RSN radio. "Until we're given those hard facts from the AFL by the end of the week we're not jumping at shadows.

"But we need a really competitive game and if that has to change to find that competitive game then we will look at that."

Despite the latest developments, Cameron said he still expects to face Essendon at Spotless Stadium.

"We'd love to play the Bombers and we expect to play the Bombers in our round two NAB Challenge (match)," he said.

"We need a competitive game because the minutes you need to get into your squad of 30 to 32 players is so important.

"We're confident we're going to be lining up at Spotless Stadium against the Bombers."

GWS kicks off its campaign against Gold Coast at Blacktown on March 7 and winds up against the Sydney Swans at StarTrack Oval in Canberra on March 22.