The 23-year-old has previously expressed his desire to return to Madrid, but reports in the media suggest Real are hoping to make a quick profit by immediately selling the forward on to an English club, possibly Arsenal or Chelsea.
"The chances that Morata will stay at Juventus are really low," Marotta told Italian media.
"Real will exercise the repurchase right and will inform us in written form in the next days. We will evaluate what to do."
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Morata, whose buy-back clause is believed to be worth around 23 million euros ($25.94 million), is currently leading the line for Spain in the European Championship, and scored two goals in the 3-0 win against Turkey on Saturday.
Meanwhile, speculation over influential midfielder Paul Pogba's future at Juventus intensified after his agent Mino Raiola confirmed talks over a potential transfer to Real have begun.
However, Marotta was quick to play down suggestions that Pogba would follow Morata to Spain.
"No official bids have arrived," he added.
"For us he is an indispensable player. Raiola is a great agent and we have a great relationship with him. Paul's development is not yet complete, and he will do well if he stays with us for the years to come."
(Reporting by Silvia Recchimuzzi; Writing by Nivedita Shankar,; Editing by Neville Dalton)
