Manchester United reportedly scouted Portugal international Bruno Fernandes during Sporting Lisbon's 3-1 win over Aves on Saturday night.
Fernandes struck his 28th goal of the season at the weekend, with the 24-year-old enjoying a remarkable campaign for Sporting.
United are said to be at the head of the queue for the attacking midfielder, who is believed to have a release clause of £86m in his current deal.
According to A Bola, the Red Devils sent scouts to watch Fernandes in action at the weekend as they consider a summer move.
The Portuguese joined Sporting from Sampdoria in 2017 and has helped the Green and Whites land two Taca da Liga crowns during the last two campaigns.
United, meanwhile, have reportedly been informed by Napoli that central defender Kalidou Koulibaly will cost £110m this summer.