Manchester United completed the signing of Porto defender Diogo Dalot on Wednesday. The Portugal under-21 international is the second acquisition in 24 hours for United manager Jose Mourinho, after the Premier League team reached an agreement with Shakhtar Donetsk to sign Brazil midfielder Fred on Tuesday.
Dalot, a 19-year-old full back, has signed a five-year contract, with an option to extend for a further year.
"Diogo is an extremely talented young defender with all the qualities to quickly become a great player for this club," former Porto boss Mourinho said.
"He has all the attributes that a full-back needs: physicality, tactical intelligence and technical quality ... In his age group, he is the best full-back in Europe and we all believe he has a bright future ahead of him at Manchester United."
United didn't reveal details of the fee, with the transfer announced on its club website.
— Manchester United (@ManUtd) June 6, 2018
British media reports suggested the deal is worth between 20-22 million euros ($23.5-26 million).
"Joining Manchester United is an unbelievable opportunity for me," Dalot said, adding that "the chance of coming to the biggest club in the world is something I just couldn't turn down."
Dalot is expected to provide competition for Antonio Valencia at right-back, with Italy defender Matteo Darmian now likely to leave the club.
Having come through Porto's academy, Dalot made his first-team debut as a substitute in February, before going on to start four league games for the Primeira Liga champion.