The Spanish frontman joined from Los Blancos two season ago, helping the Old Lady to successive League and Cup double success, but will be heading back to Spain next season as his former employers have exercised a clause in his contract, paving the way for his return.
Real Madrid have informed us of their intention to exercise the right to buy back [Morata], we are just waiting for a written offer," Marotta was quoted as saying at a public event.
"Only then will we see how to proceed, but at the moment the possibility of Morata staying are slim.
"He will leave Turin and return to Spain."
Morata, who was also the subject of interest in England, is currently on national duty with Spain, having scored two in La Furia Roja’s 3-0 Group D win over Turkey last week.
Meanwhile, Juve chief Marotta says the club has not received any offers for talisman Paul Pogba.
"We have not received any offers [for Pogba]," he said. "He is a fundamental and indispensable player for the present and future of Juventus."
He also confirmed that Dani Alves’ medical in Turin will take place next week, while revealing that Barcelona has shut the door on a possible move for Alves’ Barcelona teammate Javier Mascherano.
“Barcelona have closed things down for Mascherano,” he said.