Standard Sport reported last week that the Blues were edging towards a deal for the 23-year-old, only to see the situation change over the weekend.
Monchi went on to explain how the Catalan giants signed the France international under Chelsea noses for £42million, with a host of sizeable add-ons.
"Last Thursday, we reached a verbal agreement with Chelsea and the player,” Monchi told SFC Radio. “When everything was closed and there was a good offer, there were some doubts on Chelsea’s side and everything stopped
“Then Barca appeared. The first time they contacted was last Monday, with Mateu [Alemany, Barca sporting director]. They sent us a lower offer than what we wanted and then made an effort to put in a very good offer and closed it. Kounde agreed on the sale to Chelsea, there was an agreement with the player.
“The player was sold to Chelsea but Chelsea then had doubts whether Kounde was the profile of player they wanted. Chelsea then looked to return to negotiations but Barcelona’s offer was better.”
Chelsea are now scrambling around for new targets, with Inter duo Milan Skriniar and Denzel Dumfries having been discussed for wing-back and central defender positions.
There is long-term interest in Leicester City defender Wesley Fofana, though the player is reluctant to push for a move having just signed a new five-year deal and the Foxes do not want to lose one of their prized assets.
Bayern Munich’s Benjamin Pavard has been offered to Thomas Tuchel’s side and could be another option.