Nathan Lyon has opted against a county cricket stint this year as Australia continue to hold out hope of stumbling into the Test championship final.
Lyon signed a deal to be Hampshire's overseas player in 2020, only for that contract to be cancelled because of the COVID-19 pandemic.
Both parties left the door open for the offspinner to return in 2021.
But Lyon, who admitted he was exhausted at the end of a draining Test series against India last month, is not ready to make his debut in England's first-class competition.
"I knocked back Hampshire unfortunately," Lyon told AAP.
"I'm still looking to get over there at some stage.
"But I just don't think the timing is right to go over there now, given the pandemic."
Young allrounder Cameron Green, who holds a UK passport, also confirmed last week he will not play county cricket during the long break between Tests.
Tim Paine's side will not don the baggy green until next summer, unless they take part in the inaugural Test championship final that is set to be held at Lord's in June.
The postponement of a tour of South Africa means Australia's fate will be decided by the four-Test series between India and England, which is locked at 1-1 and continues on Wednesday.
A series draw or a 2-1 win for England will result in an Australia-New Zealand championship final.
"Obviously I'm watching that series quite closely," Lyon said.
"It'll be a different winter (either way), but that's exciting. A good chance to really get some good fitness and training done, hopefully improve my game while doing it."
Lyon recorded match figures of 10-78 in last week's Sheffield Shield clash between NSW and Victoria at the SCG.
That career-best Shield haul came after he failed to bowl India out on less helpful pitches in Sydney and Brisbane.
Mitchell Starc's match figures in the Blues' loss to Victoria were 1-104, with his sole wicket coming from the game's penultimate delivery.
Lyon defended Starc, who has attracted criticism since his ineffectual finish to last month's Test series decider.
"He's a world-class bowler. He's incredible," Lyon said.
"I'm happy for all those critics to come and put the pads on and face him.
"A talented cricketer like Mitch doesn't become horrible overnight. Mitch has all my support."
Lyon and Starc's Shield season continues on Thursday, when the Blues face Victoria at Sydney's Bankstown Oval.
