NAIROBI, Aug 28 AAP - A fitter, stronger Shane Warne is ready to go "berserk" and recapture some of his best form, according to stand-in Australian coach Allan Border.

Border said the slim, gym-going Warne was in the right physical and mental shape to start wreaking havoc in Test cricket.

"I've just got a feeling in my gut that he might just surge again and have a period when he just goes berserk," Border said.

It's a far cry from 18 months ago when Warne was at one of the lowest points of his career - struggling to take wickets in India and subject to public criticism from coach John Buchanan about his lack of physical fitness.

"He's on fire, Warney," Border said when the team arrived in Nairobi for the triangular series against Pakistan and Kenya.

"Whether he's thought to himself 'I've got to an age when I really need to take stock' or maybe initially there was a bet and he said "bugger you, I can lose five kilos'.

"He's that sort of guy, once he sets his mind to something he's pretty good."

Border, filling in for the injured Buchanan in Nairobi, was the national selector on duty in South Africa and said the transformation in Warne on that tour alone "was just incredible".

"It's up around 12 or 13 kilos that he's lost and you can tell that he feels his career has had a bit of a trough and now he's ready for another up-surge," said Border.

"That's what it looks like from the way he's bowling, his attitude, his body language - the whole thing is really positive."

Border couldn't say whether Warne - ravaged by injuries to his shoulder and fingers over the years - would regain the ability to super-spin the ball.

"But he's given himself every chance in the world that he might get some of that rotation back - only time will tell - but he can't do any more in terms of getting back in shape for it."

© 2002 AAP

This report does not necessarily represent the views of the Australian Cricket Board.