Knee injury sidelines England star Kevin Pietersen as Ashes looms England's Kevin Pietersen bats during a tour match in New Zealand. KEVIN Pietersen faces going into the Ashes underdone with the star England batsman to be sidelined for up to two months with a knee injury that may require surgery. The 32-year-old has been ruled out of Friday's third Test in New Zealand due to possible cartilage damage he first sustained in a tour match when England arrived in the country. Pietersen wore heavy strapping on his right knee during the first two Tests and struggled in the field in Wellington and Dunedin. He will return to the UK immediately and may be required to go under the knife. The injury comes at a major cost for Pietersen, who will miss this year's Indian Premier League, where he was due to earn about $2 million playing for Delhi Daredevils. However, the 94-Test veteran, who has 7499 Test runs at 49.01, is expected to be on deck for the first Test against Australia, which starts on July 10 at Trent Bridge. The worst-case scenario is Pietersen will be sidelined until early June, which would give him approximately five weeks to be ready to take on Australia. It is the second injury setback for the English, with their No.1 spinner Graeme Swann undergoing elbow surgery in the United States after being ruled out on the eve of the first Test against the Black Caps. An England and Wales Cricket Board statement read: "Pietersen experienced knee pain while fielding in preparation for the four-day game in Queenstown earlier this month, ahead of the Test series. This has failed to resolve satisfactorily. Recent scans confirm an injury to the right knee with bone bruising and possible cartilage damage to the kneecap. The 32-year-old will return to the UK for further investigations and specialist review. The injury is likely to require ongoing assessments and a likely six to eight week period of rest and rehabilitation.