The Southampton boss worked with Mourinho during his spell working as a coach under Louis van Gaal at Barcelona, and the pair formed a good friendship at Camp Nou.
He’s a great person and a very successful manager. He always has a good spirit in his teams
Mourinho’s Chelsea side have been criticised for influencing match officials during games in recent days after the west London side crashed out of the Champions League on Wednesday.
However, former Netherlands international Koeman spoke of his respect for the Blues manager, insisting that Mourinho’s former players always speak positively of the Portuguese coach.
“In my opinion he’s a nice person but I’ve got the possibilities to have time to talk about different things in life,” Koeman told his press conference ahead of Southampton’s trip to the capital.
“Maybe your opinion is different than if you see someone on the television. Maybe one side is what he likes to say or what he likes to do after the game. The other is the relationship between two people.
“I think that’s the difference but sometimes he is playing a game. Everybody knows that but if it is done in a respectful way then I don’t have problems with that.
“He’s a great person and a very successful manager. He always has a good spirit in his teams. If you speak to players who have worked with Mourinho, they are always very positive about it and impressed with the way he does his job.
“In every sport and every business if you are one of the top managers then you have to live with critics, both negative and positive but if you look at his CV, it tells you enough.”
Southampton drew 1-1 with Chelsea at St Mary’s earlier this season after Eden Hazard cancelled out Sadio Mane’s opener in the clash on the south coast on 28 December.
The Blues are unbeaten in their last five games against the Saints at Stamford Bridge since a 4-2 defeat in 2002.
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