Chelsea reached a £55 million agreement with Sevilla for Kounde this week which will see them pay £51m up front plus a further £4m in add-ons for the France international.
Barcelona are also interested in Kounde but the Spanish club have not yet submitted an offer to Sevilla due to their financial restrictions.
Kounde has agreed a five-year contract with Chelsea, who are aiming to sign one more central defender alongside the 23-year-old and Kalidou Koulibaly, who joined in a €40m (£34m) deal from Napoli over the weekend.
According to The Guardian, Barcelona have told Kounde to wait for them to send their offer to Sevilla, with Xavi keen on completing a deal.
And Spanish radio station Cope reported on Thursday evening that Kounde has decided to hold out for Barcelona to negotiate with Sevilla, and talks have now begun between the two clubs.
The situation resembles Chelsea’s move for Raphinha earlier this summer when their £55m bid was accepted by Leeds United, but the Brazil international continued to wait for Barcelona to make an approach.
Kounde has been left out of Sevilla’s squad for their friendlies against Sporting CP and Angers this weekend.
Chelsea, meanwhile, remain in talks with Paris Saint-Germain over a move for their French central defender Presnel Kimpembe.
RB Leipzig’s 20-year-old centre-back Josko Gvardiol is also on Chelsea’s shortlist but the Croatia international still has four years remaining on his current deal with the Bundesliga club.
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