Blues chief Marina Granovskaia and Sevilla director of football Monchi will hold further talks today with a view to concluding the deal for Kounde.
However, Chelsea defender Zouma was last night giving serious consideration to refusing to be used as a makeweight in the efforts to land Kounde, a scenario that would result in a major stumbling block.
Chelsea central defender Zouma wants to stay in the Premier League, preferably London.
Sportsmail revealed on Thursday that West Ham are interested in Zouma and are in discussions over a £20million move.
As it stands, Zouma’s priority is to move across the capital to join the Hammers ahead of next season.
The Blues want to use Zouma in the deal to bring Kounde to Stamford Bridge but his stance now poses a major problem.
It remains to be seen whether Zouma can be persuaded to change his mind.
Sevilla value Kounde at around £50million and Zouma’s expected inclusion in the deal would have eased the financial burden on Chelsea.
Chelsea value Zouma at around £25million – but it remains to be seen whether West Ham are willing to go as high as that.