Declan Kidney admits Ireland face their biggest match outside the World Cup when they face Argentina in two weeks.

After the loss on Saturday, Fiji at Thomond Park are the next assignment in this month's Guinness Series, but the game is being overshadowed by the importance of the Pumas' visit to Aviva Stadium.

At stake are ranking points crucial to the draw for the 2015 World Cup staged on 3 December.

Defeat to the Pumas, who were emphatic winners against Wales on Saturday, could potentially drop Ireland into the third tier of seeds.

They faced a similar situation in 2008 when they needed to beat the South Americans to remain among the second tier of seeds.

"We're there again, aren't we? It'll be a World Cup qualifier in lots of ways," Kidney said.

"That's why the next ten days will be so important in terms of selection for the Fiji game.

"We must get the right balance between testing combinations, giving guys a run and freshening things up."

"We must get the right balance between testing combinations, giving guys a run and freshening things up" - Declan Kidney

With Fiji a non-cap international, the Argentina clash is also significant in that it offers Ireland's next attempt at ending their five-Test losing sequence.

A 16-12 defeat by South Africa ensured the autumn opened amid frustration at the their failure to claim a prized scalp and conclude their worst run for 14 years.

"The players definitely haven't forgotten how to win, they're still confident in what they're trying to do; it's just a frustration. And I know they're going to click," Kidney said.

"We have had ourselves in some situations like this in the past and but we just have to stick with it because we know it will turn.

"It's a learning process, a tough one but like I've said before, I've been down this road and I know how it twists.

"This is a good group of players to work with, they're totally different to the one from 2008.

"They're full of confidence, they go to training and have been a joy to work with for two weeks.

"Inside the in the dressing room after the game they were cracked because they knew they had let one get by us again, but they're on the right road."

Kidney revealed that Lions captain Paul O'Connell is unlikely to have recovered from his back injury in time to face Argentina.