Everton have been battling to keep hold of Branthwaite since the beginning of the transfer window and have rejected two earlier bids from the Old Trafford club.
After this it seemed was the end of it, especially after United seemed to have moved onto other targets with moves for Mathjis de Ligt - a transfer still to be completed - and then signed Yoro.
Adding the talented and much sought-after French defender was a coup for the club and apparently solved their need for a new young centre-back to re-build their defence around.
However, Yoro has picked up an injury on United's American tour, which now seems likely to keep him sidelined for the rest of the year in a huge blow for the club.
So, now come the inevitable stories that United will once again return with a new offer for the Blues England international defender.
Another element to all this is the collapse of The Friedkin Group's attempted takeover of Everton, which fell through last month.
Although there are renewed rumours of a possible new owner, that leaves the Toffees currently in limbo again with no idea yet when or if a new owner will be able to take control of the club.
And it means the club have little wriggle room financially until this perpetually thorny issue can be satisfactorily resolved.
The long-term consequences of this situation are still uncertain and could mean Everton have to sell in order to ensure they can stave off a worse-case scenario at some point in the near future, such as possible administration.
Selling other players apart from the three who have already left the club - Lewis Dobbin, Ben Godfrey and Amadou Onana - would also be necessary if the Blues are to add any more new talent before the transfer window.
Parting with one of the best young defenders in Europe, would be a big decision for the Toffees hierarchy leaving manager Sean Dyche with only three senior centre-backs as the new Premier League season begins: James Tarkowski, Micheal Keane and new signing Jake O'Brien.
And it would be critical to get the best possible amount of money for the 21-year-old star who had such a superb break-out campaign last season.
If they were to sell Branthwaite, Everton would have to bring in another central defender and that might prove very challenging in this transfer window.