St George Illawarra has suffered a double blow on the eve of its Anzac Day NRL clash with the Sydney Roosters.

The Dragons lost lock Shaun Timmins with a thigh injury on Thursday morning, the former Test centre unable to complete training and ruling himself out of Friday's game at Aussie Stadium.

If that wasn't bad enough, centre Mark Gasnier was ruled out on Thursday night after scans revealed a tear in his calf muscle.

It's the last thing the Dragons needed on the eve of their clash with the premiers and competition favourites.

"That's come at a bad time, especially with Timmo," captain Trent Barrett said.

"He was great last week. Gaz's (Gasnier) been great all year."

Veteran John Cross is likely to come into the Dragons side for Timmins, with Henry Perenara or Nathan Tutt to come onto the bench.

The Roosters' only concern is second rower Adrian Morley, who has a back problem.

Coach Ricky Stuart will give the Great Britain forward until the morning to prove his fitness and rates him a 60 per cent chance of taking his place.

"Because of the quality of player he is I'm going to give him right up until the game," Stuart said of Morley.

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