Green was told this week he would skipper the club, which gave him his first Twenty20 opportunity before taking his career overseas.

The spinner claimed it was a tremendous honour to repay the Thunder, after they had stuck by him as he remodelled his action two years ago.

"They've backed me through thick and thin, and I am really looking forward to repaying the faith," Green said.

"Thunder is the club that gave my first opportunity.

"I was selected to play for them from grade cricket ... so to get this accolade while Usman is away is a good challenge."

Khawaja had only been appointed as the Thunder's captain this summer, after they let Callum Ferguson go uncontracted.

Khawaja will now miss the Thunder's season opener against Brisbane Heat on Monday night in Canberra, as well as at least their following two games.

His absence will also last longer if he is picked at No.5 for Australia or called up from the Australia A squad following his battle for the role with Travis Head.

Meanwhile Green is the Thunder's most-capped player, after joining the club for their 2015-16 success.

He has captaincy experience previously with the Guyana Amazon Warriors, leading them in the Caribbean Premier League last year.

"We had a couple of options, Sam Billings has a history of captaincy in England as well," coach Trevor Bayliss said.

"But so is Chris. And he has been with the Thunder for a lot of years now.

"He's well respected within the group. He has captained franchise cricket teams in the past."

The Thunder though have lost quick Brendan Doggett from the start of the tournament with a sidestrain.

Elsewhere, Ashton Agar has been released from Australia A duties to start the season with Perth Scorchers.

Australia's Twenty20 captain Aaron Finch also remains a chance to return from a knee issue in the Melbourne Renegades' opener against Adelaide Strikers on Tuesday.

Australian Associated Press