MANLY fullback Brett Stewart may be the latest withdrawal from Australia's World Cup squad after yesterday having a cortisone injection for a shoulder injury.

The treatment is an attempt by Stewart to overcome the problem before the Kangaroos go into camp on Saturday but Australian team doctor Hugh Hazard last night admitted the Sea Eagles star was in doubt for the tournament.

The news is a further setback to the host nation, who are yet to name a replacement for injured Brisbane centre Justin Hodges but have ruled out drafting in Penrith's Michael Jennings from the Tonga side. He is in Auckland preparing for Saturday's warm-up match against New Zealand.

Dragons centre Matt Cooper has a chronic groin problem and may require surgery.

The Kangaroos are in better shape than Tonga, who yesterday lost brothers Louis and Fraser Anderson to injury.

Tonga director William Edwards said the Pacific nation would still field a formidable side but was pushing ahead with legal action after the Rugby League International Federation refused to allow Parramatta prop Fuifui Moimoi and Wests Tigers winger Taniela Tuiaki to play because they had switched allegiances to New Zealand last year.

"I have briefed legal counsel, and the only real issue was related to costs, but we have spoken to some of our sponsors and they have agreed to help us out," Edwards said. "We are doing this as a matter of principle and because we believe the decision is unjust. Fuifui was born in Tonga, and the only time he spent in New Zealand was three years after going there on an under-18s rugby tour. He has spent more time in Australia than New Zealand."

The Jim Dymock-coached side has also lost Anthony Tupou after he was called into the Australian side last week to replace Michael Crocker. Edwards said he hoped the same thing wouldn't happen with Jennings.

"They know he's been training with us for five weeks, and he's happy to play for his country of heritage. He hasn't said anything about it us but I'm sure he wouldn't want to go," he said.