THE Roosters could be forced to play with a third-string halves combination tonight with superstar Sonny Bill Williams in serious doubt with a strain in his glutes.

Williams yesterday failed to complete his team's final training session on the eve of his first NRL game against the Bulldogs on home soil since walking out on the club in 2008. He had scans immediately after feeling it pull at training, which revealed the strain, and remains desperate to play tonight.

While named in the back row, Williams trained in and out of first receiver this week and was coach Trent Robinson's first choice to partner halfback Daniel Mortimer in the halves against the Bulldogs, with Mitchell Pearce and James Maloney unavailable on State of Origin duty for NSW.

The Roosters will monitor Williams today before making a call before kick-off tonight if he is fit to play. The club expects him to be cleared to play. If he is ruled out with the glutes strain, the Roosters will be forced to call on Newtown playmaker Ryley Jacks.

The 21-year-old has been impressive for Newtown in his first season since graduating from the Roosters' Holden Cup program last year.

Jacks has regularly trained with the Roosters first grade squad this season, but a Roosters spokesperson said he did not train with teammates during their captains run at Moore Park yesterday.

He also went to the same Queensland school - St Laurence's College - as Cooper Cronk and William Zillman.

Bulldogs coach Des Hasler said his team will be ready for Williams if he plays at five-eighth tonight.

"He could do that quite easily," Hasler said.

"He stepped in there and played a bit of first receiver already. That's an option that Trent could look at that. There is an experienced player in Daniel Mortimer on the other side. So that side's taken care of. But there are some handy people who have been running around in their premier league side as well. They have a bit of versatility there.

"He's one of their strike players. I thought he was very good in a beaten side against the Warriors. Again this week, with key players missing in certain positions, a lot of the responsibility will fall on Sonny and he'll respond. He's a player that we need to watch carefully and mark up against."

Williams told Channel 9 last night he was "100 per cent" keen to play

Roosters fullback Anthony Minichiello confirmed Williams spent time training at first receiver this week.

media_camera Sonny Bill Williams playing for the Roosters against the Warriors in round fourteen. Picture: Costello Brett

"Obviously he can ball-play, there's no doubt about that," Minichiello said.

"He's going to be playing that lock for us and sometimes back-row, where we need to get us on the front foot. And then he can ball play when he sees fit. He's pretty skilful.

"He's definitely focused. He's focused going into every game, but obviously there's a bit more focus going into this one because it's his past team."

Williams said he is not worried about the hostile reception he is likely to receive from Bulldogs fans tonight.

"There's nothing I can do about that," Williams said.

"For me it's just another game.

"This week was definitely one I was looking forward to.

"Now more than ever the boys need me because we're missing so many players."