Kevin Pietersen ruled out of Test series vs New Zealand

Kevin Pietersen was on Tuesday ruled out of next month's home Test series against New Zealand as he struggles to overcome a knee injury, sparking fears the brilliant batsman may also be a doubt for the Ashes series this summer.

The England and Wales Cricket Board said Pietersen "will have a repeat scan next week to determine when he is able to resume training," having been sidelined since the end of March because of significant bone bruising to his right knee.

"Injuries are a sportsman's worst nightmare!" Pietersen said on Twitter. "This one is hurting me the most.."

Responding to a supportive message on the social networking site, Pietersen tweeted that he had his "fingers crossed" he would be able to play in the five Ashes tests against Australia starting on July 10.

Before that, England hosts the Champions Trophy, which starts on June 6 and for which Pietersen was included in a provisional 30-man squad last week.

Pietersen first experienced pain in his knee last month while fielding in a warm-up match in Queenstown during England's tour of New Zealand. He played through the pain in the first two tests but flew home before the third test for further investigation and was ruled out for six to eight weeks.

England's first test against New Zealand begins on May 16 at Lord's, with the second taking place at Headlngley from May 24.