The Portuguese manager left Real Madrid at the end of last season, confirming his return to the London club in June.
Emenalo told the club's official website: "The first thing to say is we are happy to have Jose back. He is a very good decision maker and a trusted component in the decision-making process due to what he has achieved here.
"He came in with clear ideas of what he wanted to do, which were not dissimilar from what we were already in the process of doing, and that helped.
"I am very happy with the squad we have created. You can't always get exactly what you want but in the main we were very close."
Chelsea are unbeaten in their first three Premier League games this season.