The Daily Mail had carried reports today that United boss David Moyes had sanctioned a €30m offer for the Portugal international midfielder.
But A Bola claims that such reports are premature. United are indeed interested in the 21-year-old Carvalho - but he's under contract at Sporting until the summer of 2018.
And as a result, Sporting are in a strong position to demand the player's full release clause - reportedly worth €45m.
The report states that Sporting have not received any offer from United for Carvalho despite speculation to the contrary.
United have been heavily linked with Carvalho since the January transfer window, with club officials in Portugal on a regular basis scouting the midfielder.
He's been scouted more than 10 times this season, with United looking to strengthen their midfield heading into next season.
Moyes recruited Marouane Fellaini from Everton last summer, but United's midfield has been found lacking this term.
Carvalho is by no means the only player under consideration at Old Trafford, with Bayern Munich's Toni Kroos also thought to be a target.