Ireland's tenure at third place in the IRB world rankings is likely to be shortlived even if Eddie O'Sullivan's side complete a clean sweep of wins against the Pacific Islands this weekend.

Should Australia overcome Scotland or South Africa avenge last Saturday's defeat at Twickenham both sides will overhaul Ireland in the current standings.

Under the IRB's ranking system, Sunday's meeting with the Pacific Islands does not count as a fixture and Australia and South Africa, who were both dismantled at Lansdowne Road in the current series of internationals, can take advantage.

World Cup favourites New Zealand will remain at the top of the pile regardless of their result against Wales while France need to beat Argentina to hang on to second spot.