The defender joined Roma on loan from Leeds in the winter transfer with an option to buy set at around €20m.
The option will become an obligation if the defender hits certain targets at Roma but he has hardly played for the Serie A giants.
He has played just a minute in Serie A since joining Roma and is currently sitting on the sidelines due to an injury.
And according to Italian daily Il Messaggero, Llorente is now almost certain to return to Leeds at the end of the season.
The Spaniard has not done enough to convince Mourinho to want to buy him on a permanent deal in the summer.
His performances in training appear to have not been up to the mark and the Roma boss is not interested in keeping him at the club.
Llorente is not expected to play enough games to hit those targets that could turn the option to buy into an obligation.
It remains to be seen whether the centre-back has a future at Leeds once he returns to the club in the summer.