The Deadline Day signing of Porto left-back Alex Telles was completed by Manchester United in a £15.4million contract.
On Sunday night, the 27-year-old Brazilian international had a medical at Carrington and penned a four-year contract with the option of another year until June 2024.
After Donny van de Beek's £ 40 m arrival from Ajax with former Paris Saint-Germain striker Edinson Cavani set to follow on deadline day by signing on a free transfer, Telles has now become United's second signing of the summer.
Telles told the club's official website: "It is an immense pleasure to join a club with the prestige of Manchester United."
'You have to work hard to bring your career to this moment and now I'm coming to this club, I can guarantee I'm going to give it all in my heart to be a success here.
'I have won several FC Porto trophies and I want to continue with that at United. For this squad, the manager has a clear plan and direction and I can't wait to put on that famous shirt.
Solskjaer added: 'First and foremost, I welcome Alex to United. He is a player we have been tracking for some time and his performances over the past few years are exactly what we are looking for. He is a fighter and a winner and will add real determination and competition to the squad.
'Alex got the qualities, both as a player and as a person, that we need here at Manchester United.'