The 21-year-old Belgian starlet arrived at Stamford Bridge from Genk last summer in a £6.7million deal before moving to Bundesliga side Werder Bremen on a season-long loan.
After a string of impressive performances for the Weserstadion outfit, his agent, Patrick De Koster, has told him that the West Londoners want to keep him, despite interest from Bremen, Borussia Dortmund and Bayer Leverkusen.
De Koster has held talks with Chelsea and told the London Evening Standard: "The conversation was very positive. They are pleased with his progress and think he is ready to become part of the first team.
"The only problem is there is still no clarity about who is head coach next season."