England back-row James Haskell admits he's under pressure to keep hold of his shirt as contenders look to move ahead of him at Test level.
Haskell was a starter for England during the Six Nations but the emergence of Jack Clifford and Teimana Harrison has applied pressure.
There is also the prospect of lock Maro Itoje being used as a blindside flanker, all of which means Haskell is on his guard in Australia.
"You are always on your toes with training, the way we train is very intense and quite physical at times," he revealed to England Rugby.
"You never want to let yourself down so everyone is aware there's no complacency at all. With the two guys (Clifford and Harrison), they are quality and could easily start in any position.
"They've been fantastic and they'll be pushing everyone, just as I am as hungry to start as anyone.
"(The competition for places) never becomes an issue, and once the coaches make the decision the sign of a good squad is that the players who aren't involved make all the difference to help prepare the starting team and get behind them."
England's back-row was well beaten by Australia in their World Cup pool match as Scott Fardy, Michael Hooper and David Pocock came out on top. That game is unsurprisingly still in the memory of Haskell ahead of the first of three Tests, kicking off in Brisbane this Saturday.
"It's a huge challenge, their whole back-row performed extremely well during the World Cup," he added.
"Pocock was already a world class player but he gained legendary status after the way he performed at the World Cup, Fardy was the unsung hero and he was great and Hooper, when I came over here to play, was probably one of the best players I played against.
"We know exactly what it's about but as a player you have to have every confidence you can go there and match them. At this point in time you’re more worried about yourselves than their team."