Reports suggest Benfica's Lindelof is set to become United's most expensive defender, with the finer details of a move worth between $50 million being discussed.

Mourinho did not directly name the 22 year-old, but suggested many of the players being linked with United from Portugal were only being mentioned because of his nationality.

Linedelof's Benfica team-mate Nelson Semedo is another player reportedly being tracked by United, but Mourinho insists there will not be multiple buys in the mid-season window.

"I believe more in the summer market than in the winter transfer window," Mourinho said to Sky Sports. "There is more stability, more time, more choice. I think it is better.

"But let's see what happens. If we buy a player, we buy a player. We are not buying two, three or four.

"There is talk about so many. In Portugal on the front pages, every player in Portugal now is coming to Manchester United. 

"It is normal, the connection with me. A few seasons ago every player from Portugal was going to Chelsea and was going to Real Madrid." 

Having stressed there would not be more than one arrival, Mourinho also insisted he will not actively be looking to sell anyone in his squad during January.

"I like my squad, I want to keep my squad. 

"If we open the door for somebody to leave it is not because we push him, it is because he really wants to leave. 

"But, for me, I'll be more than happy to keep the squad as it is."