Ashton Agar is in line to play his first Test on home soil after he was added to an extended Australian squad for the fifth Magellan Ashes Test in Sydney.

Agar beat out fellow left-armers Steve O'Keefe and Jon Holland and could partner Nathan Lyon in a two-man spin attack at the SCG. Lyon and O'Keefe have both played the past two Tests at the ground that has recently returned to its former glory as the best for spin bowling in the country.

QUICK SINGLE LIVE: Australia v England day five

Agar missed the early part of the JLT Sheffield Shield season after breaking a finger on his right hand in October, but was Australia's second-choice spinner behind Lyon on their most recent overseas Test tour to Bangladesh.

Australia's 14-man squad for fifth Magellan Ashes Test: Steve Smith (c), David Warner, Cameron Bancroft, Usman Khawaja, Shaun Marsh, Mitchell Marsh, Tim Paine, Pat Cummins, Josh Hazlewood, Nathan Lyon, Jackson Bird, Mitchell Starc, Ashton Agar, Peter Handscomb.

O'Keefe, who played all four Tests in India earlier in the year, was handed a shock recall for the second Test of that tour after initially being overlooked for the younger Agar, joining him and Lyon in a three-pronged spin attack in Chittagong. Captain Steve Smith had made it clear that Agar's initial selection over O’Keefe was made with one eye on grooming him for their next Test series in India.

Having helped Perth Scorchers to victory over Melbourne Renegades in their KFC BBL clash on Friday night, Agar declared that he was bowling better than he ever has in long-form cricket.

Agar marks Shield return with four scalps

"I think so," he told cricket.com.au. "It comes down to understanding your action, what your best ball is, what you can fall back to and just thinking of getting the batter out.

"I'm not thinking about my action anymore or how the ball is coming out. All I'm thinking about is how to get the batter out at any point in time or the game situation.

"That's a really good headspace to be in as a spin bowler."

Agar cameo lifts Scorchers to competitive total

Holland, who played two Tests in Sri Lanka in 2016, was overlooked for both tours this year despite being the standout spinner in Shield cricket in recent years. He took 50 wickets at 21 last Shield campaign and after missing the first three games of this summer due to injury, picked up 11 dismissals in just two games before the mid-season break.

O'Keefe (four wickets in two games) and Agar (four wickets in one game) have also had their Shield campaigns affected by injury, while leggies Mitchell Swepson and Fawad Ahmed (16 wickets each) have led all spinners this season.

With no Shield matches at the SCG so far this summer, selectors are somewhat flying blind in regards to whether or not the pitch will take turn again and a decision on the final Test XI won't be determined until after the squad arrives in Sydney.

Paceman Mitchell Starc is hopeful of proving his fitness for his home Test having missed the current match at the MCG due to a foot injury.

A cricket.com.au poll asking readers who Lyon's back-up spinner should be saw nearly 30 per cent of respondents select Agar, narrowly ahead of Queensland leg-spinner Mitchell Swepson. More respondents said Australia did not need a second spinner (16.2 percent) than picked Stephen O'Keefe (16.14 per cent) or Victoria tweaker Jon Holland (13.64 per cent).

2017-18 International Fixtures

Magellan Ashes Series

Australia Test squad: Steve Smith (c), David Warner (vc), Cameron Bancroft, Usman Khawaja, Peter Handscomb, Shaun Marsh, Mitchell Marsh, Tim Paine (wk), Mitchell Starc, Pat Cummins, Nathan Lyon, Josh Hazlewood, Jackson Bird.

England Test squad: Joe Root (c), James Anderson (vc), Moeen Ali, Jonny Bairstow, Jake Ball, Gary Ballance, Stuart Broad, Alastair Cook, Mason Crane, Tom Curran, Ben Foakes, Dawid Malan, Craig Overton, Ben Stokes, Mark Stoneman, James Vince, Chris Woakes.

First Test Australia won by 10 wickets. Scorecard

Second Test Australia won by 120 runs (Day-Night). Scorecard

Third Test Australia won by an innings and 41 runs. Scorecard

Fourth Test MCG, December 26-30. Tickets

Fifth Test SCG, January 4-8 (Pink Test). Tickets

Gillette ODI Series v England

First ODI MCG, January 14. Tickets

Second ODI Gabba, January 19. Tickets

Third ODI SCG, January 21. Tickets

Fourth ODI Adelaide Oval, January 26. Tickets

Fifth ODI Perth Stadium, January 28. Tickets

Prime Minister's XI

PM's XI v England Manuka Oval, February 2. Tickets

Gillette T20 trans-Tasman Tri-Series

First T20I Australia v NZ, SCG, February 3. Tickets

Second T20I – Australia v England, Blundstone Arena, February 7. Tickets

Third T20I – Australia v England, MCG, February 10. Tickets

Fourth T20I – NZ v England, Wellington, February 14

Fifth T20I – NZ v Australia, Eden Park, February 16

Sixth T20I – NZ v England, Seddon Park, February 18

Final – TBC, Eden Park, February 21