After impressing on loan at Werder Bremen following his move to Chelsea in January 2012, De Bruyne was linked with a move to Borussia Dortmund. But the 21-year-old, who spoke with Mourinho on the phone ahead of Belgium's match with Serbia earlier this month, is now set for an opportunity with the Blues.
De Bruyne's agent, Patrick De Koster, told Press Association Sport: "Mr Mourinho gave a phone call to Kevin, explaining a little bit the situation for next season. Afterwards, Kevin played the game (for Belgium against Serbia), received congratulations from the coach and then he left on holiday."
He added: "A year and a half ago when he signed a contract at Chelsea, it was like a dream which became reality.
"Afterwards it was important for Kevin to put the right steps at the right moments.
"Kevin wants to play. Playing football, he became a better football player. I think he proved it staying six months more in Genk and last season in Bremen. He did very well. Now it's up to him to prove the same thing at Chelsea."
De Bruyne is one of three Belgians who could have a big impact at Stamford Bridge next season, alongside established first-team regular Eden Hazard and striker Romelu Lukaku, who spent last term at West Brom.
Mourinho offered no assurances to De Bruyne over game time, though.
De Koster added: "We didn't receive any guarantees, but it's normal in a team like Chelsea.
"It's up to him to prove like he did in the last 18 months."
Source: PA
Source: PA