The 32-year-old, who also played under Mourinho at Inter, joined the Stamford Bridge outfit in August after the club failed in their attempts to land Manchester United striker Wayne Rooney.
He will contest for a place in the starting XI with fellow forwards Fernando Torres and Demba Ba, but Mourinho confirmed the Cameroonian will get his first taste of English top-flight action on Saturday.
"He will be playing his first minutes for Chelsea in the Premier League," Mourinho said.
"I think he's a player adapted to the style of play we want in our team. Technically he is very good.
"He has a natural appetite for goals and he will give experience to a team which, in attacking areas, is very, very young."
Mourinho also dismissed any notion that the pair had a frosty relationship, after Eto'o admitted his dislike for the manager prior to working with the Portuguese at San Siro.
"Yes (I knew he felt like that)," he continued. "You have to be smart. Sometimes you say things then a few years later you are faced with a difficult situation, so it is fine.
"I had a similar situation early in my career with Deco. We know when we are on the same side, everything changes."
Mourinho added that Juan Mata is still a part of his first-team plans, despite rumours the Spain international could depart Stamford Bridge, and also admitted he was caught off guard by former club Real Madrid's decision to allow Mesut Ozil to join Arsenal.
"Mata is a player I like very much, he is a player I trust a lot and he will fight for his position," the 50-year-old added.
"He will be a player who sometimes starts, or on the bench. With so many games I will make strange decisions in your eyes.
"Sometimes I think further than just the next match.
"I'm surprised Madrid let Ozil go. That's football.
"Mesut left a big club but comes to the biggest league in the world to a club with big ambitions. He was happy to do it. I have good memories with him, I wish him well, but not that well because he plays for a direct rival."
