New Zealand v England: Kevin Pietersen must man up and deal with his knee problem, says Andy Flower With back-to-back Ashes coming up this year and five weeks in the Indian Premier League before that, he will not want it to degenerate further, which could make Thursday's Wellington Test decision time between his short and medium-term interests. One man who has appeared to overcome what seemed to be chronic injury is Stuart Broad, who bowled with almost as much purpose and fizz as before the many physical ailments he has suffered over his career had begun to erode his will. Before Dunedin, Broad, has endured a frustrating winter of Test cricket in which he went wicketless in India and damaged the fat pad on his left heel, a problem he reckoned was "incurable but manageable," with luck. He also lost the vice-captaincy of the Test team, to Matt Prior, though as Flower pointed out on Monday that was more to do with the uncertainty over his heel problem than any loss of form. There is a school of thought that feels Broad's form with the ball has suffered due to him curbing the excesses of temper that used to land him in trouble with match referees but which also drove the devil in his bowling. They probably had a point except that his three for 118 in New Zealand's only innings in Dunedin was not far off the old Broad but minus the bad behaviour. "I thought his pace was good and his body language and run-up were purposeful and strong," said Flower. Stuart is a world-class performer who has altered the complexion of a number of international matches for us. Having him fit and firing is a huge factor in our game. He is a naturally feisty guy. We all have to find a balance between aggression and doing things right on the field. As an England player he has the responsibility to find that balance as well. Broad, as well as Steve Finn, who had a far better first Test with bat than ball, could be the men to unlock New Zealand's batting in Wellington if James Anderson doesn't find the swing that saw him take seven for 130 in England's win there last time. The pitch at the Basin Reserve is said to be the quickest and bounciest in New Zealand, conditions that should suit tall, fast, nasty fast bowlers like Broad and Finn as well as batsmen like Pietersen, should his knee hold firm.