Reports from the continent have suggested that terms have been agreed to transfer the 25-year-old Portugal international to Old Trafford.
But speaking after Tuesday night's 2-1 Capital One Cup semi-final first-leg defeat at Sunderland, Moyes said: "No, that's not true."
Opposite number Gus Poyet was even more reticent when asked about Brighton midfielder Liam Bridcutt's decision to hand in a transfer request.
The 24-year-old Scot is understood to have submitted his request with the Black Cats having been engaged in talks over he and winger Will Buckley for several days, but without making a breakthrough to date.
But asked about the situation, Poyet replied: "That's nothing to do with me."
Not a bad player but what's with the Billy Ray Cyrus haircut?- shea666