MELBOURNE - Australia on Tuesday added Ashton Agar to their squad for next week's fourth Test against India, raising the prospect of the home side playing two spinners in Sydney. Agar, who scored a memorable 98 in his Test debut against England, will give national selectors another spin option at the Sydney Cricket Ground in addition to off-spinner Nathan Lyon.

The squad is otherwise unchanged after the third Test in Melbourne finished in a draw, with all-rounder Mitchell Marsh having been ruled out of the Sydney game with a hamstring injury. "I think Ashton's bowling very well at the moment," skipper Steve Smith said. "He's a good addition to the squad. We'll see how the wicket is in Sydney when we get there and we'll go from there."

On the possibility of playing two spinners at the traditional spin-friendly SCG, Smith said: "We'll just have to wait and see what the wicket is like. Last year it had a bit of grass on it and previously it's been quite a spin friendly wicket. So I think it's more of a see how the wicket is and if he's needed then he can play." Australia have already won the Border-Gavaskar Trophy series after wins in Adelaide and Brisbane heading into the fourth Sydney Test.

SQUAD: David Warner, Chris Rogers, Shane Watson, Steve Smith (capt), Shaun Marsh, Joe Burns, Brad Haddin, Mitchell Johnson, Ryan Harris, Nathan Lyon, Josh Hazlewood, Mitchell Starc, Peter Siddle, Ashton Agar.