Canterbury’s Tony Williams has been added to the Bulldogs’ long list of casualties with the giant back-rower expected to miss the rest of the NRL season due to a pectoral muscle tear.

The representative forward will have surgery next week after suffering the injury this week in preparation for Monday night’s clash with competition leaders St George Illawarra.

Williams joins centre Tim Lafai (knee), utility forward Pat O’Hanlon (ankle) and Brett Morris (hamstring) and James Graham (knee) in the casualty ward at Belmore.

But there is a chance both Graham and Morris will play against the Dragons with the pair to be given until the last minute to prove their fitness for the ANZ Stadium clash.

The news on Williams, announced by the Bulldogs on Friday, is a huge blow to Des Hasler’s side who meet the Dragons after the bye and a thrilling 41-34 win over Canberra.

“Scans late yesterday revealed the damage, with the back-rower now booked in for surgery next week,” the Bulldogs said.

“The injury suffered is more than likely season-ending for the Cabramatta junior with the rehabilitation for such an injury to be approximately six months.”

Representative prop David Klemmer, fresh from his State of Origin debut for NSW, hopes to run out with Morris and Graham on Monday.

Morris will be desperate to get back on the field ahead of Origin II at the MCG on June 17 after missing the series opener.

“It’s up to Des and the rehab team to get him fit but he doesn’t want to risk the injury,” Klemmer said.

Graham has played just one match since the epic defeat to South Sydney on Good Friday, a 27-minute cameo against the Roosters in round 10 that was ended by concussion and a knee injury.

“He’s had an up and down season so far but he’s still got a couple more days to go,” Klemmer said.

“He’s got more tests and that to do, so we’ll see if he’s out there on Monday.”