New Zealand fast bowler Shane Bond has been given until Sunday to prove his fitness after suffering a recurrence of his existing back problem in Australia.
Bond was cleared of a potentially career-ending stress fracture of the spine last week
The paceman is definitely ruled out of the Black Caps' one-dayer against England on Tuesday with the problem.
And team manager Lindsay Crocker says the 31-year-old will be sent home if he fails to recover ahead of Sunday's third game against Australia in Perth.
"If he doesn't get right, we will make a call post-Adelaide," said Crocker.
"Perth is our earliest realistic expectation of getting him fit, but we will see how he goes over the next three-to four days."
However, there was better news for all-rounder Jacob Oram, who has recovered from a hamstring injury to face England.
Oram, 28, has taken 99 wickets in 87 ODIs and can also be a big hitter in the middle to late overs of an innings.
Another all-rounder, Scott Styris, pulled out of a provincial match in New Zealand on Friday with a strained calf muscle but could travel to Perth if he proves his fitness this week.
New Zealand are currently winless in the tri-nations CB Series, having lost to Australia twice and England in the Tasmanian capital Hobart.