Those calling for Irish rugby great Brian O’Driscoll to retire might eat their words this weekend, according to All Blacks captain Richie McCaw.

O’Driscoll and McCaw are set to go head to head for the 14th time in Dublin on Saturday, with the decorated Irish centre still seeking his first victory.

The recent mixed form of O’Driscoll has prompted opinion from Irish critics that the 34-year-old should have retired last year or after being dropped for the third and final Test of the British and Irish Lions series against Australia four months ago.

McCaw, 32, has nothing but praise for O’Driscoll, whose 135 Tests place him second on the all-time list behind the 139 of former Wallabies captain and halfback George Gregan.

“I have a huge amount of admiration and respect for the way he plays,” says McCaw, who is fourth on that list on 123.

“He’s always been hugely competitive, which you expect from top players.

“Whatever people say, I know he’s a classy player. We’ll probably see that again soon.”

O’Driscoll, who has lost the Irish captaincy to lock Paul O’Connell, will know himself when it is time to hang up the boots, McCaw says.

His theory is that players in their early 30s can still perform at full capacity if they are prepared to make sacrifices.

“When you’re younger, you do it easily. But as time goes on, it’s that desire and that willingness to go to those dark places – mentally and on the training pitch. If you can’t do that properly, then your own form’s going to follow.

“I’m sure some players know deep down when that time comes.”

McCaw is thankful he hasn’t reached that point as he sets his sights on a fourth World Cup appearance in 2015.

“I still get a huge thrill out of it and still feel like I can play better.”