It was on the ground floor of the new Carnegie Pavilion last August, after being named man of the match for a brilliant 149 in the second Test against South Africa, that Pietersen said: "It's not easy being me" in the England dressing room, setting in motion the chain of events that led to his spell in the wilderness.
He is missing again, this time through injury, but Cook agreed that Pietersen's expected return for England's next Test – against Australia at Trent Bridge in July – would raise the stakes for Nick Compton and Jonny Bairstow, the batsmen whose places he most obviously threatens.
"We all know that's the situation," said the captain, delivering a more upbeat update on Pietersen's recovery from his knee injury than the version provided by the bowling coach, David Saker, earlier in the week. "He's progressing well. There is some more information over the next couple of weeks that we will receive but chatting to him at Lord's he sounded positive, and fingers crossed. With injuries you're not quite sure how they're healing but it sounded as if he was making good progress.
"I think we all know when Kevin comes back and he's fit, his record and his class demands that he plays for England pretty much. So that creates competition for places and the guys in the changing room will be desperate to score runs. That's good for us in this game because we need as many runs as we can get.
Cook had not come across as a great fan of Yorkshire in lamenting the occasional hailstorms that had forced England to practise inside. "I don't think we have had a two-day warm-up here where we haven't been indoors on at least one of the days," he said. So the reference to Last of the Summer Wine in praising his new opening partner was probably accidental.
"Compo's got the shirt at the moment, and he fully justifies that selection," Cook said when asked whether the local hero Joe Root was pressing for a move up the order. "He's forced his way in with the amount of runs he scored at Somerset, and we've had some really good starts at the top of the order. I think Rooty has always opened the batting so he sees himself as an opener. I'm sure at some stage in the future you will see Joe Root opening the batting.
"We all know selection can change but he [Compton] has shown us the determination and the talent he's got at the top of the order and the character you need to fight there and he's got to continue doing that."
New Zealand will go into the Test with four seamers after Daniel Vettori , the veteran spinner who had travelled to Leeds in the hope of replacing the injured Bruce Martin, decided that his 34-year-old body was not up to the strain of a Test.
Vettori has not played a first-class match since July 2012 and has recently been troubled by an achilles injury. Brendon McCullum, the captain who will also keep wicket in a Test for the first time in three years despite his own back and knee problems, said: "He [Vettori] didn't scrub up that well today and just the confidence to go into a five-day game with the workload he's had was just a bridge too far."
McCullum remains confident that Vettori will return to international cricket in next month's Champions Trophy, and has welcomed the former captain's presence in the dressing room as New Zealand aim to square the series. "He brings a lot more facial hair, that's for sure," he said in tribute to Vettori's luxuriant beard.
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