The midfielder played all but one league game in a season long spell with the Bundesliga side last season, and their sporting director Thomas Eichin has told German reporters that the club would be willing to have the 22 year old with them once again.
The Belgium international is currently training with Chelsea’s youth squad after manager Jose Mourinho criticised his performance in the League Cup third round victory over Swindon Town last week.
That appearance was just one of four that he has made for the Blues since signing from Genk in January 2012.
Borussia Dortmund also registered their interest in De Bruyne during the summer, though his inclusion in the starting line-up against Hull City in the opening game of the season seemed to suggest that his future was very much at Stamford Bridge.
However, Mourinho must now decide whether the play would benefit more from another spell away from the club.