''Mourinho has done great work to change tactics but stay successful,'' Rijkaard told the BBC today.
''Mourinho follows his personality, staying close to his own way. He chooses that and he has been very successful with it. I can only have respect for that.'' European champions Barcelona face Chelsea at the Nou Camp today in a Champions League Group A match.
Barca are in joint second spot in the group, level with Werder Bremen on four points, and five behind Chelsea after their 1-0 defeat at Stamford Bridge two weeks ago.
''We have already played several times against Chelsea and we know how they play,'' Rijkaard said.
''They are not as quick as they were in the counter-attack two years ago.
''They have some players with a lot of talent. Chelsea are playing in a different way, with Michael Ballack closer to the opponent's goal. He has freedom and Michael Essien and Frank Lampard can overlap him.
''The main thing is that when they don't have the ball they are very well-organised, they do not give away much space and it's difficult to do something against them.'' It is the third successive season that the two clubs have been drawn together in the competition.
Chelsea knocked Barcelona out 5-4 on aggregate at the first knockout round stage in 2004-05 but the Spanish club won 3-2 on aggregate last season en route to winning the final against Arsenal in Paris in May.
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