Manchester United have signed full-back Diogo Dalot from Portuguese champions Porto.

Dalot only made his first-team debut in February but the 19-year-old has moved to Manchester on a five-year deal, with an option for a further year, after Premier League runners-up United activated his release clause.

With out-of-favour Italian Matteo Darmian expected to leave Old Trafford and manager Jose Mourinho desperate to provide veteran right-back Antonio Valencia with more competition, United have turned to the Portugal Under-21 international.

Dalot made seven appearances in all competitions in 2017-18 as Porto won the Primeira Liga crown for the first time since 2012-13 and reached the Champions League's last 16.

A Porto youth product, Dalot played in six matches of Sergio Conceicao's triumphant domestic campaign, which ended Benfica's run of four successive league crowns.

Dalot also played at left-back in Porto's goalless draw in the second leg of their Champions League tie with Liverpool, who won 5-0 on aggregate in March.

The news comes a day after United announced they had reached an agreement to sign Brazil international Fred from Shakhtar Donetsk.