Argentina could make a surprise appearance in Sydney to play a one-off Test against the Wallabies during this year's Tri Nations series.

After repeated requests from Argentinian officials seeking more Test matches against other southern hemisphere nations, SANZAR late last year issued an invitation to the Pumas to play South Africa, Australia and New Zealand during the Tri Nations. The matches are proposed for gaps in the scheduling of the tournament, which is being held from July to September.

Under the proposal, Australia would play the Pumas when South Africa and New Zealand are involved in a Tri Nations Test. The plan is for the Pumas to play one match each against the three SANZAR countries, but the match would not be part of the Tri Nations series. Instead, it would be used solely to promote Argentinian rugby.

However, the conditions under which SANZAR invited Argentina last December may well preclude them from accepting. SANZAR has stipulated that the Pumas field their best team, and that the team includes, without exception, all of their northern hemisphere stars. An Argentina back-up team will not be acceptable.

That Argentina have yet to reply to the SANZAR invitation indicates they are having serious problems guaranteeing that they can field their best team.

The main stumbling block is that all of Argentina's best players are involved in European competitions, and the numerous United Kingdom and French clubs which employ them are unlikely to give them permission to play during what is usually their rest period.

As well, Argentina rugby holds little power over its players. Its local competition is in turmoil, with factions fighting over control of the game, while the main body has for some time been struggling financially.

This forces Argentina's best players to travel offshore to earn a living because there is basically no money in the local game. It is understood that Argentina's World Cup squad has not yet been paid.

Australian Rugby Union officials yesterday were aware of the SANZAR invitation, but were unsure whether they would shortly have to find dates and venues for Test matches.

"To date the ARU are not aware of any reply from Argentina," a spokesman said last night.

SANZAR officials will travel to Buenos Aires at the end of this week to meet their Argentine counterparts.

SANZAR needs a reply by early next month, or the invitation will be withdrawn.

It could ultimately rely on the International Rugby Board, which has backed Argentina's involvement in the southern hemisphere tournaments, putting pressure on the European clubs to allow their Pumas players to be involved in the one-off Tests.

The IRB is also expected to make New Zealand's and Australia's lives easier at the next World Cup with a change to the seeding process.

After endless criticism of the World Cup seeding system, which is based on what had occurred at the previous tournament, the IRB is expected shortly to decide to use a more updated world ranking formula. The World Cup rankings are expected to be decided by the international rankings a year or so before the event.

This would delight Australia and New Zealand, especially after they both disappeared at the quarter-final stage of last year's World Cup tournament.

It would also avoid the embarrassment of the 2011 World Cup hosts - New Zealand - being placed on the second tier of the draw, below South Africa, England, Argentina and France.

■ In Super 14 news, the ACT Brumbies will be without Adam Ashley-Cooper for half of the tournament.

It was confirmed yesterday the Test centre would be sidelined for at least six weeks because of a serious ankle ligament injury.

Adding to the Brumbies' woes is the expectation that their, and the Wallabies', captain and centre, Stirling Mortlock, will not return from injury until about the same time.

The Brumbies will be forced to field a raw centre combination against the Highlanders in Canberra on Saturday evening as inside centre Gene Fairbanks is also sidelined. He has a neck injury.