Sky Sports - England in Australia

Important

Meanwhile Cook remains optimistic that Pietersen will be back for the main events in perhaps the highest-profile year in English cricket history.

"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.

"There are quite a lot of sportsmen who play when they're not 100% fit.

"If you asked Jimmy (Anderson), through certain times in his spells, and Broady [Stuart Broad] when his heel (injury) was coming on, they felt it.

"He did, but felt he could get through the game and produce good enough performances to justify his selection."

Ultimately, England have had to be advised by Pietersen as well as their medical experts.

"The scans can only tell so much. It's got to be how the player feels as well," said Cook.

"My knee might, does, feel different to KP's.

"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.

"We've just got to have a bit of luck with the scan in a couple of days' time."{"count":3,"widgets":[{"name":"Live Test Cricket (88335579)","id":1,"type":"tvprogramme","content":{"participantId":"19","participantName":"Live Test Cricket (88335579)","paParticipantId":"88335579"}},{"name":"Additional Media 1","id":2,"type":"media","content":{"mediaTypeId":"11","imageDim":"null","mediaPosition":"1"}},{"name":"Additional Media 2","id":3,"type":"media","content":{"mediaTypeId":"11","imageDim":"null","mediaPosition":"2"}}]}