From this Friday, on Amazon Prime, we will be able to watch 99, a three-part documentary series on Manchester United’s Treble. Everyone who was there seems to be involved, giving their memories of a hectic few days in May, 25 years ago. Except for one glaring absentee. According to the show’s producer – a certain David Beckham – Roy Keane refused to participate because he prefers not to look back on a time that, due to his enforced absence from the Champions League final that was the culmination