Chelsea's need for Manchester City's Nathan Ake has grown stronger amid fears Juventus defender Matthijs de Ligt could choose Bayern Munich over a move to London.
Chelsea are willing to offer a higher fee than the Germans of around £68m.
The Blues had identified de Ligt as one of their key transfer targets and offered Timo Werner as part of the deal but were unable to reach an agreement with Juventus.
Bayern have now overtaken Chelsea in the battle for de Ligt, with the German club's head coach Julian Nagelsmann and sporting director Hasan Salihamidzic having spoken to the Dutchman.