Western Australia batsman Ashton Turner has been ruled out for at least a month with a broken finger which means he is unlikely to be in contention for Australia's T20Is against Sri Lanka and Pakistan.

Turner, who returned from shoulder surgery at the beginning of the season, picked up the injury during training ahead of the Marsh Cup game against New South Wales.

"Ashton sustained a fracture to his right index finger at training this week," WACA sports science medicine manager, Nick Jones, said. "After reviewing the injury with specialists, he will require a period of approximately four-six weeks before being able to return to play."

Turner was part of Australia's most recent T20Is, against India in February and his renowned finishing skills - which he showed during Australia's record ODI run chase in Mohali on the same tour - would have put him firmly in the frame to be included for the Sri Lanka and Pakistan series as Australia plan for the T20 World Cup next year.

The first of three T20Is against Sri Lanka is on October 27 in Adelaide with that series followed by three matches against Pakistan in early November.

Turner had started the season in promising style with a brisk half-century in the opening Marsh Cup match against Victoria.

After being left out of Australia's World Cup squad he took the decision to undergo significant shoulder surgery to enable him to field and eventually bowl to full capacity.

New South Wales were also forced into an injury change for their first home match of the season after Kurtis Patterson picked up a quad injury playing grade cricket at the weekend.