British and Irish Lions centre Brian O'Driscoll has expressed his gratitude at being given another opportunity on the tour and is optimistic about his side's chances against Australia.

The Ireland international will be making his fourth Lions tour outing having made his debut in 2001 against the Wallabies before captaining the side when they were beaten 3-0 by New Zealand in 2005.

O'Driscoll also tasted Lions defeat at the hands of South Africa in 2009, but is confident that his side can turn their recent poor record around this summer.

"It was all new to me in 2001. I was delighted being on the tour and getting into the Test team," O'Driscoll told Sky Sports News. "I look back and realise what a massive missed opportunity that was.

"We had them in the second Test and we didn't finish them off. You subsequently look back having been on two other tours and realise how difficult it is to win a series. The great thing about another opportunity is that there are no boundaries to what you can achieve.

"I'm the eternal optimist and go down with the thought that we can absolutely win a series. We will work hard towards doing that and hopefully put ourselves in a position to do that."

The Lions open their tour with a clash against the Barbarians on Saturday in Hong Kong.