Manchester United had scouts in Portugal on Saturday to watch Porto's 2-0 win over Pacos de Ferreira with goalkeeper Diogo Costa on their watchlist, according to reports.
Costa has hugely impressive for Porto, featuring in 28 of their 29 league games as they fight for a Primeira Liga title. Sergio Conceicao's side sit one point off first-placed Benfica, conceding just 19 goals all season.
United are reported to be exploring a move for a first-team goalkeeper this summer, with David De Gea entering the final few months of his contract. The 32-year-old is expected to pen a short-term deal, but another poor display in Thursday's defeat at Sevilla has raised regular concerns about his quality on the ball.
