Ireland's opening autumn international against Australia at Croke Park heralds the arrival of another special milestone for their enduringly brilliant captain.

With 93 Ireland caps and six Test appearances for the Lions in the bank, O'Driscoll will become the 11th player to achieve the century when he faces the Wallabies.

Only Australia openside George Smith, named on the bench for Sunday, has reached the mark faster.

In a neat piece of symmetry, O'Driscoll made his debut as a 20-year-old replacement against the same opposition in 1999 - and the similarities between occasions will not end there.

"I was really looking forward to my first cap and didn't start feeling nervous until the fireworks went off when Australia came on to the pitch," said O'Driscoll.

"I wasn't expecting that. Once the whistle went for the start of the game all those nerves evaporated. I still have those nerves - if you don't the mind isn't sharp.

"You have to be on the ball against Australia so if you're eating your pre-match meal without any problem then there's an issue there.

"You need to be forcing your food down. The butterflies focus the mind and get you ready for combat."