Australia all-rounder Shane Watson is excited about betting at number four, because it will be a challenge to face more spin and will allow him to play a more active role in the bowling department.

Watson missed most of the series against South Africa with a calf injury and was unable to bowl, but he will now slot in at four thanks to Ricky Ponting's retirement and Phil Hughes being drafted in at three.

This will allow skipper Michael Clarke to use Watson for longer spells as a bowler, because he will, in theory, have more time to recover from being in the field before having to pad up against the Sri Lankans.

Watson said on Sky Sports of batting at four: "Both Michael and (coach) Mickey Arthur think it's a good place for me to bat.

"I really am seeing it as a big positive. One, for my batting side of things, but also for my bowling, to hopefully be able to really contribute that little bit more with the ball because I feel like I have got a bit more to contribute with the ball.

"Batting at four means that Michael can use me that bit more and hopefully I can provide some impact."

He continued: "I don't think I'm really going to have to change anything at all. Hopefully the bowlers are going to be a little bit more tired, the ball's going to be a little bit older and the wicket's going to be more worn as well.

"The challenge for me is to be able to continue that mindset, like I was when I was opening and having success.

"I do know I'm going to be facing spin a lot more coming in and batting at four. That's something that I've been conscious of really working on, having a better game-plan to be able to go in facing spin straight up."

The first Test against Sri Lanka begins in Hobart on Friday.