New Delhi:The question mark over Zaheer Khan's fitness has once again raised the issue of whether fast bowlers around the world are finding it difficult to handle a year round cricket schedule. Although Zaheer has been cleared for Sunday's India-Pakistan game, this is not the first time he has had injury problems. The Baroda pacer was forced to return home from Australia after the third test in Melbourne and it was repeated again during the Pakistan series earlier this year. Zaheer failed to play the last two tests because of a hamstring injury. Host of players But it is not just Zaheer. Ashish Nehra has been in and out of the team and had a long lay-off after the World Cup. Jason Gillespie has also suffered from injury as has strike partner, Glen Mcgrath. New Zealand's Shane Bond has also been out of cricket for more than a year. The long list of injuries has now led cricket boards to consider a rotation system where fast bowlers play only a certain number of matches each year. Perhaps ensuring that the bowlers play fewer matches could be one way of keeping them fitter for a longer duration.