Manchester United have sent scouts to Portugal to watch Benfica duo Ruben Dias and Florentino Luis.
Sport Witness says United scouts were at Benfica's clash with Braga on Sunday to specifically cast an eye over the duo.
United failed with a bid to sign young centre-back Dias in July, while defensive midfielder Luis has shown good form early on this season.
The report claims Lyon, Bordeaux; Sevilla, Villarreal, Celta Vigo, Atalanta and Premier League new boys Norwich have also been scouting the duo.
Both players have featured in Benfica's opening four games of the Primeira Liga season.
