Okdiario says Real have already struck personal terms with the Belgium international and are now in negotiations with Chelsea over a fee.
Chelsea are willing to sell for €50m - a fee deemed too rich by Real for a player with less than a year to run on his current deal.
Instead, Real insist €38m would be a more realistic valuation, but are willing to compromise to get closer to Chelsea's assessment.
Pundit Eduardo Inda revealed on El Chiringuito that Real will offer €38m upfront and include a further €7m in bonuses to get the deal over the line.
Real are confident the offer will be enough to convince Chelsea to sell.