Wednesday, 27 September 2017
He is a huge admirer of the Belgian midfielder as sees him as the perfect fit to replace Michael Carrick next summer.
Mourinho also watched Atletico's Antoine Griezmann and £85m-rated Saul Niguez, who he is a long-time fan of, during the match.
United are still hopeful of landing the French striker next summer after a number of failed bids in the last window.
The Red Devils are understood to be lining up a £88m bid for the 26-year-old.
An Old Trafford source said: “Jose sent scouts to the game to look at a number of players, but most importantly Nainggolan.
“He is a big fan of his. Griezmann was also looked at, but we know everything we need to about him already.
