The 32-year-old Cameroon international, signed from Russian club Anzhi Makhachkala in the summer transfer window, is likely to start on the bench when Chelsea take on Everton at Goodison Park in the late afternoon game on Saturday.
Mourinho said: "He will be selected and when you are selected and you are a striker you play, you start or finish the game but normally my attacking players when selected play because it is the area where I make more changes during the match. So normally he will play his first minutes for Chelsea in the Premier League.
"He is a player adapted to the style of play we want in our team which is a bit contradictory to the general style and philosophy in the Premier League.
"We are not any more a physical, direct team. We want to use the qualities of our attaking players in a different way.
"His movement is very intelligent. He knows exactly the kind of movement he has to do to give continuity to the attacking game. He has a natural appetite for goals and he will score a few goals for us and he will give us experience.
"Everybody is very young, for example against Bayern Munich (in the Super Cup) Andre Schurrle, Oscar and Eden Hazard all were all under 22. So Samuel is a player to add experience to a young part of the pitch."
Mourinho insisted that it was imperative to have three main strikers at his disposal and Eto'o takes his place along with Fernando Torres and Demba Ba in the squad.
"If sometimes I have to risk one point to get three I do it almost every time," Mourinho explained. "Against Manchester United I didn't because I felt it was an important point. But I like to have strikers on the bench and I like to finish matches with two of them. That's why this group of three is fundamental. It is very rare I don't make changes."
Mourinho and Eto'o have had their differences in the past and when Eto'o was with Barcelona he vowed he would never play for the self-proclaimed 'Special One'.
Mourinho, however, laughed off their differences and said: "You have to be experienced and smart and know the football world is very small. Sometimes you say things and a few years later you are faced with a difficult situation.
"I had a funny situation with (Portugal midfielder) Deco. Deco was in Porto, I was in Leiria. In November we play Leiria against Porto. In the match we exchanged some hot words and two weeks later I was Porto manager.
"So I come into the dressing room and the first thing I did was look at Deco and he was looking to his knees, but when we are on the same side everything changes. And Samuel with me at Inter Milan was a golden period for both of us and here he is again."
Mourinho admitted he believed Tottenham had been the big winners in the summer transfer window, strengthening their squad with the cash they received for Gareth Bale, but he was also surprised that Real Madrid had let £42m Mesut Ozil join Arsenal.
"I'm surprised Madrid have let him go but that's football," said Mourinho. "That's the market. Ozil left a big club but comes to the biggest league in the world. If Madrid sold him it was because it was good for them. I am happy a big player like him comes to the Premier League."
Mourinho also insisted Spanish midfielder Juan Mata, who has been left on the bench recently, had a future at Chelsea.
He said: "He is in the same plans as all the others. He's a player I like very much. A player I trust a lot and who will fight for his position like everyone else, sometimes starts, sometimes on the bench, sometimes maybe he has not to be selected like everyone else."