Brian O'Driscoll has warned Ireland's World Cup hopefuls a selfish approach to Saturday's clash with Scotland will only harm their chances of selection.
Ireland head coach Eddie O'Sullivan will use the trip to Murrayfield to fill the handful of positions still available with the back row and back three the only areas yet to be settled.
Wingers Brian Carney and Tommy Bowe are jostling for a ticket to France while Stephen Ferris, Jamie Heaslip, Keith Gleeson and Alan Quinlan are competing for the fifth back row spot.
But O'Driscoll, who will lead Ireland for the 38th time on Saturday, has told the borderline cases that sacrificing the team's needs at the altar of personal ambition will not aid their cause.
He said: ‘In a lot of cases guys are uncertain of whether they'll be in for the World Cup, so this is there last chance to prove their worth.
‘They want to make it difficult for Eddie to leave them out.
‘So I'll be expecting some big performances from certain guys. But the best way to turn in a big performance is to play well as a team.
‘A lot of international rugby is taking your opportunity when you're given it, whether it be through injury or good form or whatever.
‘It's all about taking that opportunity on the day and I'll just be saying that to these guys on Saturday afternoon.’
Ireland open their World Cup campaign against Namibia on September 9 and then face Georgia before meeting France and
Argentina in two pivotal Pool D games.
O'Sullivan already knows his first-choice starting line-up, although the Ireland boss has declared he is willing to make changes if form dictates he must.
Unlike in previous World Cups Ireland now have genuine depth beyond the first XV and O'Driscoll believes it is the greater playing resources that makes the current squad a more formidable outfit than four years ago.
He said: ‘There's far more competition for places these days. Bar maybe one or two places, the squad for Australia in 2003 basically picked itself.
‘But there's a huge amount of spots up for grabs this time around.
‘It means that players are pushing one another an awful lot more than four years ago and that means that the standard has increased hugely.
‘I think as well that we had a very good XV in 2003, but maybe our strength in depth slipped off after that. I don't think that's the case anymore.
‘We've got quality players to come in when guys are out injured. They're putting pressure on the guys with the jerseys because they're playing so well.
‘We're getting the very best out of everyone. Nobody can afford to feel comfortable.’
