British and Irish Lions lock Paul O'Connell claims there is "savage competition" for places in the squad ahead of Saturday's first Test against Australia.
O'Connell, the 2009 tour skipper, is expected to line-up alongside Alun-Wyn Jones against the Wallabies in Brisbane, however Ian Evans, Geoff Parling and Richie Gray are all pushing hard for Test places.
And the 33-year-old insists he is taking nothing for granted despite having playing in the last six Tests for the Lions.
"Every tour has been different," said O'Connell. "The dressing-room is a lot quieter than on previous tours. There isn't a hell of a lot of talk coming up to games. There is no bravado or talk.
"There is savage competition for places, and guys are very eager to play as well as they can individually.
"I think if you look at the back-line and the way the backs have been playing it's certainly a step up. Forwards-wise, I think we've performed really well as well.
"We've carried well, done well at the breakdown at times and it's as good as any team I've been on, but you don't really know until you get to the Tests.
"I was on the tour in 2005, and to this day it's still probably the toughest rugby experience of my life.
"I had this big expectation of what a Lions Tour was going to be. Unfortunately, I didn't play well. A lot of us didn't play well, and it was a very tough place to be after the tour.
"2009 was a little different, but at the same time it was a missed opportunity. For a lot of guys it's like the World Cup. It's your shot at forever, that kind of thing."
The Lions have won all five of their tour matches so far and are big favourites to secure their first series success since 1997.
However O'Connell accepts that the Wallabies will pose a massive challenge.
He added: "We've a very tough three weeks ahead of us.
"Australia are a really good side, they have a lot of incredibly talented players and the next three weeks will be really tough and will be a lot different to what we've experienced (so far) in terms of intensity and physicality.
"It will be a big step up for us."