Perth - Key New Zealand paceman Trent Boult has back trouble and must prove his fitness in training to play in this week's historic day-night Test against Australia, coach Mike Hesson said on Monday.
The left-armer has an irritated disc in his back, similar to the complaint which hindered his new ball partner Tim Southee during the first Test loss in Brisbane.
Boult did not bowl in the two-day tour practice game against a Western Australia XI in Perth over the weekend, and needs to show he can deliver at full pace without hindrance to play in Friday's third Test in Adelaide.
"We'll have to see how he travels to Adelaide but he's certainly an option for the Test," Hesson told reporters.
"We've got a plan and he's got to bowl flat out two days out from the Test (Wednesday). If he's able to get through that he'll be considered for the Test."
Boult has been recovering from back problems which forced him out of the one-day series in England earlier this year and the tour of South Africa and Zimbabwe in August.
Hesson said bowling on hard pitches in back-to-back Tests in the Australia series had not helped Boult.
"I guess when you come back from a back injury there's an element of confidence and also being able to know when you can push through and when you can't," Hesson said.
"He's in good hands with the physio. He's an outstanding physio so I'm sure we'll know more when we get to Adelaide."
Boult took six wickets in the Brisbane and Perth Tests, including Australia captain Steve Smith three times and star opener David Warner twice.
Apart from Boult, New Zealand's other seamers in the touring squad are Southee, Doug Bracewell, Matt Henry and left-armer Neil Wagner.