The Belgian midfielder spent last season on loan at Werder Bremen, but the manager wants to keep him at Stamford Bridge for the forthcoming campaign.
The 22-year-old told the team's official website: "The manager said he has a lot of confidence and brought me back because he believes in me. I have to show that on the pitch, but it is nice when the trainer has confidence in you.
"I have to work hard and see what happens in pre-season. After training you can have a good laugh, but in the session he likes discipline and that everybody is working hard on the field.
"We have a lot of young players and it will be good to go on tour and stay together, and get to know each other and other places. It is always fun."
De Bruyne joined Chelsea from Genk in January 2012.