New Zealand's preparations for this week's first Test against Australia received a boost on Monday when batsman Nathan Astle said he was a likely starter in the match despite a back complaint.

The 33-year-old Astle missed the tourists' nine-wicket loss to New South Wales in Sydney last week because of the injury, but said he has an 80 percent chance of playing in Brisbane on Thursday.

"It's still a little bit sore," Astle told reporters at Brisbane airport.

"But it's got a little bit better," added Astle, who averages 37.80 in 64 Tests including nine centuries.

"It's just short, sharp pains and a general ache as far as twisting, turning and running.

"(My chances are) 80-20. I'm hopeful I can play. If I get a jab (injection) that will help me."

Captain Stephen Fleming (viral infection) and spinner Daniel Vettori (shoulder soreness) also missed the four-day match in Sydney.

New Zealand are also sweating on the fitness of opener Mathew Sinclair, who has hamstring soreness after top-scoring with 88 and 79 against New South Wales.

The tour match was New Zealand's only warm-up game for the two-Test series, which includes the second Test in Adelaide on November 26-30.