Juventus have rejected United's opening offer, thought to be in the region of £86million, but their resolve is to be severely tested in the coming days.
Since joining Juventus, Pogba has gone on to win the Scudetto in each of his four seasons in Serie A, and has accumulated a total of 178 appearances.
Manchester United boss Jose Mourinho wants to sign Monaco right-back Fabinho in a £22m transfer deal this summer, according to reports in the British media.
United's executive vice-chairman Ed Woodward, who chose to skip the first part of the pre-season tour to China, met Juventus directors Giuseppe Marotta and Fabio Paratici, as well as Raiola, on Tuesday to discuss a possible transfer.
Another new man, Zlatan Ibrahimovic, is a notable absentee on the tour but will make his United bow later this month after Mourinho afforded the striker more time off following Euro 2016.
And if Pogba's all-white message is really a nod and a wink to Florentino Pérez, rather than a call for peace and love, then maybe Manchester United are swimming against the tide anyway...
France and Juventus midfielder Paul Pogba at Stade de France, Paris, July 10. But Pogba's choice now appears, realistically, to be between staying at Juventus, which he is happy to do, or moving to Old Trafford.
That would see Pogba's fee exceed that of current record-holder Gareth Bale, who cost Real Madrid €100.8m when he moved from Tottenham Hotspur in 2013.
It is understood Woodward could head to China for the second friendly against Manchester City in Beijing next Monday, but he did not travel for United's clash against Borussia Dortmund in Shanghai on Friday.