Monchi insists they were in a situation where they had to accept Liverpool's offer.
He said: "Regrets? At that time we needed it, it was a very important offer, then the numbers of (Kylian) Mbappé and Neymar blew up the market.
"This sale was necessary for us, now the price would have been even higher.
"When I arrived there was already an offer from Liverpool and the player had already given the OK for the transfer."