The Italy international has fuelled speculation that he could be on the move this summer amid reports that the Serie A champions are ready to cash in on him for the right price
The Italy international admits that a summer exit from the Turin club could be in the offing if head coach Antonio Conte no longer sees him as an indispensable player.
Marchisio recently insisted he is keen to remain at Juventus, and revealed there has been no concrete offer from either United or the Ligue 1 outfit, but hinted that he could be forced to look for a new club in the near future.
"Juventus have stated that my own intentions are decisive when it comes to my future, but there are obviously two parties involved," the 27-year-old was quoted as saying by Corriere dello Sport.
"I will have to talk to Juventus to find out whether I'm still an important player like before. If that's not the case, it's only normal that I will start looking elsewhere.
"Of course, I feel proud when I hear of the interest of Monaco and Manchester United, even though nobody has called me at this point."
Marchisio has a contract with Juventus until the summer of 2016.