Traore has spent the last 18 months on loan Vitesse Arnhem but will remain at Stamford Bridge for the upcoming season.
“I’m very happy to be here,” Traore told Chelsea’s official website. “I get to work with some of the best players in the world and one of the best managers.
“I am trying to do my best in every training session right now. It’s something nice to have the support of the manager but I have to prove that I deserve to be here. I have to work hard, do my best and take my chance.
“I think my loan was very good. I learned a lot. I had a period of adaptation in the first six months then after I had a full season with the team including pre-season. It was much better.
“I learned a lot tactically, I also learned how to play without the ball, to defend, to play as a team, and I think I improved my mentality during my loan.
“All in all I was able to improve my performances and it was a good step in my career.”
Traore’s first-team chances could be boosted by the departures of Salah and Juan Cuadrado, with both players expected to complete moves to Serie A.
Reports claim Juventus still want to sign Cuadrado despite the impending arrival of Julian Draxler, while Salah’s agent dropped a hint that his client is on the verge of joining Roma after tweeting a picture of the Giallorossi’s badge.
“He doesn’t belong to my squad and he’s not staying here,” Mourinho said about Salah on Sunday.
“The important thing is that he plays like he did at Fiorentina, so I’m happy with him going on a loan. Italian football is difficult football to play, especially for attacking players. So if it’s not Fiorentina it’s Roma or Inter or Juve — I don’t know. Maybe he has a loan.
“He’s a good boy and a good player. He needs more top-level football so I’m happy with any decision him and the club make.”