Reports earlier this week have claimed that Watford were keen on bringing the youngster, an impressive force at right back over pre-season, to Vicarage Road for the 2017/18 campaign.
Fosu-Mensah only made three starts last term and needs more game time, but Jose Mourinho will only make a decision over certain outgoings following the UEFA Super Cup clash with Real Madrid on Tuesday.
And according to the Sun‘s Lee Astley, De Boer, who oversaw Fosu-Mensah’s development at Ajax before he moved to Old Trafford in 2014, will enter the race to sign the powerful 19-year-old on a loan basis.
The Dutchman himself has recently noted this aim for next season is to develop further under Mourinho’s tutelage, emphasising the value that comes with playing alongside top players and working under a manager with the Portuguese’s pedigree and track record on a day-by-day basis.
That said, the prospect of working once again under De Boer, who knows Fosu-Mensah well, at a Premier League side may be an offer that the teenager will find hard to refuse – especially if United do, as rumoured, complete the signing of Serge Aurier from Paris Saint Germain.