Real Madrid and Barcelona will be seeded in pot one for this afternoon's Champions League group stage draw.
The La Liga giants will be amongst the favourites to lift the trophy at Wembley in May, but could face stern competition when the groups are drawn in Monaco at 4.45pm (UK time).
Valencia have been seeded in pot two, alongside English champions Manchester City and Schalke. Meanwhile in pot three, Serie A winners Juventus have been placed with nouveau riche Paris Saint-Germain.
Borussia Dortmund are the toughest test lurking in pot four, but Ligue 1 champions Montpellier are another team to avoid.
Malaga, who beat Panathinaikos on Tuesday to qualify for the group stages for the first time in their history, are also in pot four, but cannot be drawn against another Spanish club at this point in the tournament.
The opening fixtures will take place on September 18/19, with the last round of games scheduled for December 4/5.
Pot One: Chelsea, Barcelona, Real Madrid, Manchester United, Bayern Munich, Arsenal, Porto, AC Milan.
Pot Two: Valencia, Benfica, Shakhtar Donetsk, Zenit St Petersburg, Schalke, Manchester City, Braga, Dynamo Kiev
Pot Three: Olympiakos, Ajax, Anderlecht, Juventus, Paris St Germain, Galatasaray, Lille, Spartak Moscow
Pot Four: Borussia Dortmund, BATE Borisov, Dinamo Zagreb, Malaga, Montpellier, FC Nordsjaelland, Celtic, CFR Cluj