Diogo Dalot has completed his medical at Manchester United ahead of his proposed move from Porto, according to Sky sources.
The 19-year-old, who is understood to have a €20m (£17.4m) release clause in his contract at the Estadio Dragao, underwent a medical with United on Tuesday.
United have already agreed an undisclosed fee for the full-back, who made his first-team debut for Porto in February.
Dalot is set to become United's second signing of the summer window, after the club agreed a deal to sign Brazil international Fred from Shakhtar Donetsk.
The 25-year-old completed a medical on Monday and is now set to join for a fee reported to be in excess of £50m.
"Manchester United is delighted to announce it has reached an agreement with Shakhtar Donetsk for the transfer of Frederico Rodrigues de Paula Santos (Fred)," the club said in a statement on their website.