Pietersen joins England as mentor as McCullum reveals he drove the appointment

Kevin Pietersen has joined England's coaching staff as a mentor ahead of next year's 50-over World Cup, with head coach Brendon McCullum saying he drove the appointment.

• Pietersen has joined England's white-ball teams as a specialist mentor in the build-up to next autumn's 50-over World Cup in South Africa.
• McCullum said Pietersen had "thought I was joking" when the initial approach was made to the 46-year-old.
• McCullum said Pietersen has been tasked to "look across the environment and challenge me privately around ways we can improve things."
• England has instructed Pietersen not to focus on any single discipline.