Manchester United have reportedly made an official approach for Spanish youth international midfielder Saul Niguez.
The 13-time Premier League champions, who defeated League One Sheffield United 1-0 in the FA Cup on Saturday, are understood to have made an opening £15m offer for the Atletico Madrid starlet according to local press.
The 21-year-old, who is a Spain Under-21 international, has scored five goals in 21 appearances in all competitions for the La Liga leaders this season.
Niguez, who began his youth career at rivals Real Madrid, is highly-rated under Atletico boss Diego Simone.