The Belgium international initially joined the Blues from Genk in January 2012, but spent the last campaign on loan at Bundesliga side Werder Bremen.
Mourinho made it clear on his return to the Stamford Bridge hot seat that the likes of De Bruyne, 22, and fellow promising young Belgian Romelu Lukaku, who was on loan at West Brom last season, are very much part of his plans for the new campaign.
It is an opportunity De Bruyne intends to take. Speaking to the club's official website, he said: "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."
Like Manchester United and Arsenal, Chelsea are making the most of some lucrative promotional opportunities while in the Far East, where they will play matches in Bangkok, Kuala Lumpur and Jakarta before then heading to the United States where they will take part in the Guinness International Champions Cup, along with the likes of Everton, Inter Milan, Real Madrid and Los Angeles Galaxy.
De Bruyne is expecting a testing schedule to sharpen up for the new Barclays Premier League campaign, which will open against Hull on Sunday August 18 as part of the first wave of live matches announced today.
"The tour of Asia will be difficult for us, with the heat and the humidity, but we will see what happens and we just have to prepare ourselves well for the season," he said.
"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."