After months of negotiations, United announced the world record deal for the Juventus midfielder in the early hours of Tuesday morning.
It marks the find piece of the jigsaw laid out by Mourinho after his appointment as United boss, with Pogba following the acquisitions of centre-back Eric Bailly, the creative Henrikh Mkhitaryan and striker Zlatan Ibrahimovic.
“Paul is one of the best players in the world and will be a key part of the United team I want to build here for the future,” the Portuguese said.
“He is quick, strong, scores goals and reads the game better than many players much older than he is. At 23, he has the chance to make that position his own here over many years.
“He is young and will continue to improve – he has the chance to be at the heart of this club for the next decade and beyond.”