The Argentina international has been linked with a move to Old Trafford for much of the past year, and Marotta told Italian daily La Gazzetta dello Sport one way a Juve star can expect to leave the club (h/t Alex Porter of the Manchester Evening News.
When quizzed on United's talent in the South American, Marotta replied: "He's a very strong player, on which we aim a lot. But Dybala will undoubtedly remain at Juve, also because we do not need to sell anyone, unless the same player asks."
It's little wonder United have become one of the suitors most frequently linked with Dybala, a player who has earned comparisons with compatriot Lionel Messi, as discussed by former Juventus star Michael Laudrup:
Porter noted Dybala is "very close" with Paul Pogba, who traded in the Bianconeri's colours to head back to Od Trafford in the summer of 2016, with his arrival in turn sure to help the club attract more star talent.
The Old Lady had to recover from Pogba's loss just as it did Arturo Vidal the year before and Leonardo Bonucci the year after, suggesting Turin's top club has the means to survive the departure of talented individuals.
Dybala arrived at Juve from Palermo in the summer of 2015 and has since won back-to-back Serie A titles, as well as achieving successive trophy wins in the Coppa Italia.
The 24-year-old has also established himself as something of a long-range and dead-ball specialist, as Statman Dave noted:
Speaking to French magazine France Football in November, Dybala suggested his loyalties aren't tied to any one club in the long run, indicating he has ambitions to play elsewhere than Juventus (h/t Goal's Robin Bairner): "I don't know if I'll be at Juventus for life and I can't even say that this will not be my last year in Turin."
Comments such as that won't stir much confidence in the club's hierarchy that their talisman is planning to stick around.
Dybala signed a contract in April last year that isn't due to expire until 2022, and Marotta previously indicated to Mediaset Premium the club has no need for release clauses, valuing trust above all else (h/t Goal's Iain Strachan).
By those principles, United perhaps can have Dybala when he wants them, although the Red Devils will still need to satisfy Juventus' asking price for the player in order to complete a move.