Ryles pulled up sore during a training session at WIN Stadium yesterday, with Dan Hunt expected to start tonight and second-rower Kirk Reynoldson called into the team.

While Ryles will have to wait until Monday for scans, Dragons medical officials are hopeful he will only be out for one week.

A loss to the Sharks would place the Dragons NRL finals chances on a knife-edge, with teams queuing up behind them for top eight positions.

Ryles' front row partner Justin Poore, who was yesterday named in the preliminary Australian World Cup squad, declared he was ready to step up against the fierce Sharks pack.

"Rylesy has been a massive part of our team," he said.

"I'll have to step up without him, but Dan is definitely a young fella on the way up and it's a big chance for him against the Sharks.

"With Dan and Kirk Reynoldson coming into the team we'll be ready for them."

While the Dragons are set to be missing Ryles, Ben Creagh and captain Mark Gasnier, the Sharks welcome back State of Origin superstar Greg Bird.

Bird said the Sharks were desperate to bounce back from recent losses to finals contenders Manly and Brisbane.

The Sharks premiership credentials took a hammering as they were demolished 34-6 by the Sea Eagles at Toyota Park last month.

"Manly turned up on fire that day, but it was not the sort of game we want to be playing," Bird said.

"We really need to come and show we're not pretenders."

Bird, who has fully recovered from a knee injury and will start at lock, said he was expecting Gasnier to overcome a leg injury and play tonight.

"He's a pretty tough customer," Bird said.

"I'm sure he would be keen for the local derby.

"I don't know whether they were playing games at the start of the week or he is genuinely injured.

"We've been training as if he is definitely going to play."

However, the Dragons last night denied Gasnier was set to be a shock late inclusion.

"Unless he gets a new leg in the morning, he won't be playing," a Dragons spokesman said.