KP put his body on the line - Cook

Alastair Cook praised Kevin Pietersen's commitment to the England team and insisted that his knee injury had become too painful to play through following the decision to rule him out of the final Test in Auckland and all cricket for up to two months, including IPL.

But Cook was hopeful that Pietersen, who joined in with fielding drills at Eden Park before flying home on Thursday evening, may yet be available for the home series against New Zealand which begins in mid-May. The key target, however, remains the Ashes and, before that, the Champions Trophy with the former certainly the priority. England's one-day side has learned to live without Pietersen but they would be weakened by his absence for the Champions Trophy.

In the present, the Test top order will be less stable without him even though he has not been at his best during this series, hindered, it has emerged, by the knee problem since the warm-up match in Queenstown. The injury has been managed for two Tests, with Pietersen scoring 73 in Wellington and spending most of the time in the field, but the deciding match has been considered not worth the risk with Cook making it clear that the move would have been made regardless of the opposition.

"We're getting robbed of him in this game. He hasn't been 100% fit, but he's put his body on the line trying to play for England," he said. "That's all you want from all your players. He felt he could get through, and we felt he could get through, those two games. This game might be a step too far.

"It's important now we don't jump to too many conclusions. He goes home and gets to see the specialist, and sees exactly what's wrong with him. It's important he's fit as soon as he can be. You do look sometimes at future planning, but I think if this was an Ashes Test match he wouldn't be playing in it.

Surgery may yet be needed to correct Pietersen's problem, which could be caused by cartilage damage, but Cook is hoping for positive news from the scans that will be taken in a few days.

"At the moment, it's not great for English cricket that one of our senior and best players has an injury concern going into the summer. That's not ideal. If the injury is not so bad, as we hope, and it's just a bit of rest and no operation needed then on the plus side he gets a bit of time off and is ready to go for the Ashes."

Pietersen's injury means that three senior players will now be undergoing recovery ahead of the English season with Graeme Swann and Tim Bresnan at different stages of recuperation from elbow surgery. Alongside the injuries to Stuart Broad and Steven Finn in India, where both fast bowlers flew home before the end of the trip, England's resources have been tested.

"We all know in the dressing room that you are going to miss players at certain times through injury. That is what happens, in any professional sport. Touch wood, we can get into the summer with a fully-fit squad now. Bressy and Swanny are recovering well from their operations.

"Come the first Test against New Zealand, you want a fully-fit squad. That doesn't always happen, and when it doesn't you've got to have the strength in depth - that's why I think we're in quite a healthy position as an England squad, that we can call on very good players to come in.

Jonny Bairstow will replace Pietersen in the middle order and will have to battle against the modern problem of coming into a Test without any cricket behind him. Brendon McCullum, the New Zealand captain, was respectful of the back-up England have in their squad but did not pretend that the loss of Pietersen wasn't significant.

"He's one of those who can take the game away from you pretty quickly so even though he wasn't at his best in this series he was still able to make an impact in the last Test," he said. "From their point of view they still have some good options, but they certainly aren't Kevin Pietersen."

For Pietersen, his injury brings an early end to a six-month period which also started with him out of the team but for very different reasons. He was "reintegrated" during the Test series in India, with significant success, not least the monumental 186 he scored in Mumbai, followed by an unremarkable one-day series there in January before being rested for the limited-overs matches in New Zealand.

Cook, who was a central figure in getting Pietersen back in the side following the problems of the summer, has been delighted with his contributions.

"That innings in Mumbai was a fantastic one at a very crucial time, and that shows his worth to the team. Not many people could play that innings, and that's why we need him in an English shirt as often as we can.

"It's great to have him back. I said at the beginning of the winter, in India, you want to be able to pick from your best squad. We managed to do that, and he's fitted in really well. It's just a shame that his winter has ended a little bit early with his knee."