Martyn Williams knows he has to impress against Pumas

Martyn Williams will make his final Wales appearance at the Millennium Stadium today against Argentina - and then hope he has done enough to feature in a fourth World Cup.

Williams readily accepts the clock is ticking on a 15-year Test career highlighted by two Six Nations Grand Slams, three British  Irish Lions tours and the captaincy of his country, which he regains against Argentina this weekend.

The Cardiff Blues flanker will be 36 the day before Wales arrive in New Zealand for their World Cup campaign.

Whether he boards the flight on August 31 is coach Warren Gatland's call. For his part, Williams accepts his chances are not great.

Sam Warburton, Wales' World Cup captain-in-waiting, has nailed down the No 7 shirt, while young Ospreys openside Justin Tipuric is viewed by many as a possible selection bolter.

The combined effect is that Williams, who wins his 99th cap today, has got it all to do as Gatland assesses those final few squad vacancies.

"Look, when I was left out the Six Nations squad last season I thought that was me done and dusted," said Williams.

"But then I was pulled into the World Cup training squad of 45 and I've had a good summer's training and been given the opportunity again.

"Everybody gets frustrated watching and so, yes, I am glad to get a run.

"For a few of us who haven't had a chance, there is the incentive that, with things still up in the air, a good performance will help."

Gatland is due to announce the Welsh squad for the World Cup on Monday.

Other World Cup warm-up games today see Ireland play host to France in Dublin, while Scotland entertain Italy in Edinburgh.

* Press Association