PERTH - New Zealand spinner Daniel Vettori is expected to be cleared to play in Friday's tri-series match against South Africa despite suffering a heavy head knock last night.

Vettori's head struck the ground hard as he fell backwards while attempting to take a catch during last night's dramatic loss to Australia at the MCG.

He bowled two more overs before leaving the field and later underwent precautionary tests.

The Kiwis flew to Perth today with Vettori expected to be fit for their last round-robin match against the Proteas at the WACA when they'll attempt to clinch a finals berth.

Star allrounder Chris Cairns said on arrival that the Black Caps had not lost confidence as a result of Australia's big fightback to win last might's match.

"We are still confident of course, we're still leading the competition so we are one win away from cementing a place in it," Cairns said.

However, he was not sure if he would be able to bowl in Friday's match. "We are going to reassess it [his back] and wait and see, after a long journey over here, it's a bit stiff."

A New Zealand win would secure the Black Caps' position in the finals while South Africa and Australia will decide their fates in their match on Sunday in Perth.

© 2002 AAP