Melbourne: Australian cricket's two marketable stars Michael Clarke and Mitchell Johnson are still undecided on signing up for Cricket Australia's new-look Big Bash next summer.

The two cricketers, who have also shunned million dollar Indian Premier League contracts, are reluctant to commit to next year's Champions League Twenty20 tournament as Australia have a busy international schedule.

The Herald reported that even if Clarke does play he will sign with one of Sydney's two franchises out of loyalty to New South Wales.

The daily reported that Sixers boss Stuart Clark had a brief chat with Clarke and Thunder, who are based at ANZ Stadium, hoped the Test captain's western suburbs ties will see him don the electric green.

"I think it would make sense for Michael to think very seriously about the Thunder because he's going back to his roots, really, out there," Thunder chief John Dyson was quoted as saying by The Herald.

Johnson will announce on Monday whether he would sign for Perth Scorchers or miss the domestic Twenty20 tournament to focus on the Test series against India.

"We want him to be part of the Scorchers and he very much wants to be part of our set-up. The only thing he's trying to get his head around is does he want to commit to a Big Bash League contract, because there are things that come with it like Champions League, etc."

"He's got to be clear in his head that he wants to do that and he'll let me know on Monday. He's certainly not signing anywhere else. It's either the Scorchers or he won't be available for Big Bash," Perth coach Mickey Arthur told the daily.

The Big Bash will clash with the India series and Australia's Test players will be available for only one or two matches with their franchises.