The former Lyon defender now has a £53m buyout clause in his Barcelona deal, which makes him very appealing to United.
The Mirror reported earlier this month that Barca are struggling to match his demands and Man Utd are hoping to take advantage of the situation by triggering his £53m release clause this summer.
Mourinho would be willing to offer Umtiti around €9m in wages per season to make the move to the Premier League.
The Spanish publication said on their Friday front cover [9 March] that Mourinho already tried to sign the France worldwide during the January transfer window and will redouble his efforts this summer.
Novak Djokovic ousted in Indian Wells
A backhand victor gave Federer the only break of the opening set but, mid-way through the second, rain forced them to depart. World number one and defending champion Roger Federer , meanwhile, was unable to complete his opening match due to rain.
Barca are said to have already started contract renewal talks with the Cameroon-born defender, but reports claim they can not match United's said offer.
He joined the Spanish club from Lyon in 2016 and has gone on to establish himself as the partner for Gerard Pique in the heart of their defence.
However, it would be similarly unsurprising if United were interested in a 24-year-old who has made 30 appearances for one of Europe's top clubs this season in defence, missing games only for a muscle injury and occasional suspensions.
SPORT add Barcelona are convinced they will get the approval from Umiti that he will stay, but they want him to lower his demands.