The Bulldogs' NRL title defence appeared in tatters after halfback Brent Sherwin was lost for the season with a broken thumb and winger Matt Utai faced a three-week ban for a high tackle.

It compounded news that the NRL return of stars Sonny Bill Williams and Willie Tonga had been postponed again after both suffered setbacks in their recovery from knee injuries.

Sherwin underwent surgery and is out for up to six weeks, joining a star-studded Bulldogs injury list that also includes Hazem El Masri (knee), Luke Patten (ankle) and Trent Cutler (ankle).

Veteran Bulldogs doctor Hugh Hazard admitted he had "never seen anything like it".

"Not with so many serious injuries keeping players out for such long periods of time, no," he said.

"We've had a couple of seasons where we have had a couple of injuries to key players that have kept them out for a while but not so many key players all at once.

"It's extremely frustrating. To go from the penthouse to the cellar in a year due to injuries is very frustrating but that's the nature of the game I suppose."

Queensland centre Tonga had initially been pencilled in to return on Friday night against Parramatta and Williams was originally set for a comeback in a fortnight.

But Hazard said they were "week to week" propositions after both suffered knee swelling in their rehabilitation.

"Sonny Bill aggravated the injury. I don't know how far that has set him back - it's week to week," he said.

Brought to you by AAP © 2024 AAP