Maybe Chelsea and Barcelona are destined to keep facing one another until they at last overcome their mutual antipathy. These clubs learnt that their clubs would meet for the third consecutive season in the Champions League. The referees will be toughening themselves as much as their players. Anders Frisk, the referee in 2005, retired, and Chelsea raged over the dismissal of Asier del Horno by the Norwegian referee Terje Hauge at Stamford Bridge. Barcelona went on to take the Champions League itself. The pairing of Manchester United and Celtic brought an evocative cross-border rivalry. Gordon Strachan, manager of the Scottish champions, had put all that aside recently when he called Sir Alex Ferguson the best manager of his generation "by a million miles". Arsenal, with Jens Lehmann voted goalkeeper of the tournament, know they flourished at a far higher level on their path to the final against Barcelona in May. Don’t miss the UEFA Champions League as it returns to your screens live on e.tv. The first round of games begins on Tuesday 12 September at 20:30 when Chelsea face Werder Bremen. Manchester United takes on Celtic on Wednesday, 13 September at 22:15.