Shane Warne has called on Nathan Hauritz to prove he is the number one spinner in the country after endorsing his selection ahead of Tasmania's Xavier Doherty for the first Ashes Test.

Doherty, who bowls left-arm orthodox, was a surprise inclusion in an extended 17-man squad named yesterday, with National selection panel chairman Andrew Hilditch publicly declaring the national selectors face a big decision in the spin department.

The pair will go head-to-head during this week's Sheffield Shield clash between New South Wales and Tasmania at the SCG.

But Warne believes Hauritz has already done enough to cement his spot for the Brisbane Test.

"I think Nathan Hauritz is our number one spinner, he has a very good record in Australia and I'm sure he'll get first chance," Warne said today.

"I had a chat with him just before the Boxing Day Test last year and talked about being positive.

"I said 'mate, you're bowling well, get some right fields, work with Ricky (Ponting) to get the right fields and bowl to get someone out. Ask yourself how am I getting them out and if you ask how am I getting them out that naturally gives you a positive mindset'.

"And if he does that he'll be fine."

But while he prefers Hauritz for the first Test, Warne believes 27-year-old Doherty is ready to answer the call if required.

"If he (Hauritz) doesn't do well, a bloke like Doherty is pushing and Steven Smith is pushing, so there are options and that's a good sign for Australian cricket," he said.

"But I think Nathan Hauritz will get first chance, and he deserves it.

"He looks good (Doherty), I've worked with him a bit, not in a while, but whenever I worked with him he looks very good.

"He's definitely not a big spinner of the ball and that's something he's trying to work on, to spin it more, and this summer he looks like he's spinning it more, and that's great.

"I'm sure he'd do a very good job if picked."

Meanwhile, Warne is also expecting big things from England off-spinner Graeme Swann this summer but says the 31-year-old can no longer rely on the element of surprise.

"Graeme Swann is the number one spinner in the world and the most improved cricketer in the world, so everyone is expecting him to do really well," he said.

"Expectation is on him for the first time which is different, and he's coming in as leading wicket taker for England.

"So it's a different feeling for him but I think he'll do really well and I'm impressed with what he did this summer in England while I was commentating over there.

"He was fantastic."

Swann took 22 wickets at an impressive 12.22 in the recent four-Test series against Pakistan and has been the pick of the bowlers for England so far on his first senior tour of Australia.

Former England captain Tony Greig agrees Swann looms as a major factor in the upcoming series.

"He's obviously bowling quite well," Greig said.

"They (Australia) need to come to terms with him really quickly, they need to sort him out.

"I'd be inclined to have a go at him.

"He's an ordinary finger spinner. He doesn't really bowl a doosra.

"He gets a bit of curve and bowls a straight on ball but has an incredible record of getting wickets in his first over and LBWs.

"I think he probably is (the number one spinner in the game).

"His record speaks for itself."