Sydney - Samoa were sweating on injuries to captain Jack Lam and young scrumhalf Scott Malolua on Sunday after a credible showing against the Wallabies in their final Rugby World Cup warm-up.

Bristol flank Lam left the field after taking a knock to the eye while Reds' Malolua dislocated his shoulder during the 34-15 defeat in Sydney.

"Young Scotty dislocated his shoulder and they put it back in and we're yet to find out how bad it is," said coach Steve Jackson.

"Our captain went off as well, he took a knock to the eye, so hopefully both those guys are OK, but obviously Scotty is our main concern at the moment."

The Samoans, who made the World Cup quarter-finals in 1991 and 1995, go into camp in Japan on Tuesday ahead of their first game against Russia with Jackson positive about their chances.

While the Wallabies exploited gaping defensive holes in the first half, scoring four tries, the Pacific islanders tightened up in the second period and dotted down twice themselves.

It narrowed the gap to seven points before late tries from Dane Haylett-Petty and Matt Toomua put the game beyond reach.

"These warm-up games, I think they've done their job in what we needed and expected, it's been a perfect build-up," said Jackson, a former assistant coach at the Blues who took over a year ago charged with restoring the team's fortunes.

The New Zealander has improved performances on the field, notching up recent wins over Tonga and a New Zealand Heartland XV before they fell to Australia.

"We're just about there," he added.

"If we can stop making silly mistakes, we're right in the fight and we'll take some real good positives out of that game.

"Although we lost the spirits were high after the game, knowing we can compete with teams that like to play fast football."

Samoa will also play Scotland, hosts Japan and Ireland in a tough World Cup Pool A.