Ruud Gullit believes Chelsea face a huge task to qualify for the Champions League knockout phase after being drawn with Porto, Atletico Madrid and Apoel Nicosia.
The former Chelsea boss feels their group is as hard as the one labelled by many as the 'group of death' which contains AC Milan, Real Madrid, Marseille and FC Zurich.
He said: "It's a tough group because Porto and Atletico Madrid are very good sides at the moment. Atletico could be one of the dark horses for the competition. I saw them a couple of times this year and they impressed me, especially with the way they qualified so easily.
"The thing is with Porto they have experience of the Champions League and know how to survive. I don't think AC Milan's group is worse than Chelsea's. It's will tough for the teams in both groups. They will have to really dig in."
Chelsea keeper Petr Cech is fearful of playing in Cyprus where they will face minnows Apoel Nicosia. The Czech No1 said: "They have a lot of passion for the game. It will be a tough test for us there because the atmosphere will be crazy."
