Astle scored the fastest double Test century

New Zealand batsman Nathan Astle has pulled out of his contract with Derbyshire to have knee surgery.

Astle, New Zealand's highest-ranked one-day batsman and the holder of the world record for the fastest Test double century, will be operated on after the World Cup.

He will need six months rehabilitation which means he will not be able to honour his contract.

Astle said: "It is incredibly frustrating having to say no to Derbyshire but I want to play for New Zealand for another couple of years and I don't want to jeopardise that.

"It might get sore at the World Cup but I don't want to miss that for anything.

"I think we can manage the problem there with a sensible workload, lots of Voltarins [anti-inflammatory tablets] and just the adrenaline of the occasion."

Astle, who played one season for Nottinghamshire, was contracted to Derbyshire from June to September.

His unavailability could mean the county offer an extended deal to Pakistan's Shahid Afridi, who is currently contracted for April and May.