Those mysterious Sky Sources are at it again.
Louis Van Gaal was only named as new United manager earlier this week but already he has been linked with a string of names as he seeks to rebuild the side.
Bayern Munich's Toni Kroos and Arjen Robben were two players believed to be on his wanted list, though interest in the former is believed to have waned.
Now McCarthy has been thrown into the mix, with the article even claiming Tom Cleverley may be offered in exchange in order to sweeten the deal.
This is certainly one of the more left-field transfer rumours to emerge so far this summer, even if McCarthy has enjoyed an outstanding season.
There are also several reasons why I think it won't work out.
For starters Everton are under no pressure to sell. Like Leighton Baines last summer, the Blues are in a position to turn down big money bids and would only consider letting McCarthy go for an outrageously high transfer fee, something I cannot see United offering.
Secondly, McCarthy is only a year into a five-year contract under a manager he has flourished working under, both at Everton and Wigan. Manchester United are a huge draw I admit, but McCarthy has no real need to leave just yet and Everton can continue to match his ambitions - for a few more years at least. After all we have just finished two places and eight points ahead of a very average Man United side.
Thirdly, Roberto Martinez has already revealed he intends to offer McCarthy improved terms so this transfer rumour seems very timely. There is a lot of activity and manoeuvring by players, agents, managers and officials at this time of year and this rumour seems like an attempt to force Everton into pressing ahead with those contract negotiations.
A quick glance on Twitter suggests the Man United fans were not too happy with the rumour, perhaps blinded by the disastrous Marouane Fellaini deal and the fact they clearly mustn't have watched McCarthy play this season.
The 23-year-old was outstanding last year and one of the central blocks upon which we must build the side around next season. He would be an outstanding signing for United and a player I desperately don't want to leave.
The fact United fans cannot see this and have already dismissed him is just another reason why he is better off at Goodison where he is appreciated by players, manager and fans alike.