Manchester United have signed Brazil left-back Alex Telles from Porto and say Atalanta winger Amad Diallo will join the club in January.
Telles signs on a four-year deal, with the option of a further year.
The 27-year-old, who has one cap for his country, moves to Old Trafford for a fee of 15m euros (£13.6m) plus 2m euros (£1.8m) in add-ons.
United have agreed to pay 21m euros (£19m) for 18-year-old Diallo with another 20m euros (£18.2m) in add-ons.
The club say he will join “subject to medical, personal terms and work permit”.
They have been monitoring the teenager for the past three years as he came through the ranks at the Italian club.
The Ivorian scored on his Serie A debut in October 2019 and has made three substitute appearances in Italy’s top flight.
Diallo has not featured for Gian Piero Gasperini’s side this season but was the second player born in 2002 to score in one Europe’s top five leagues – England, France, Germany, Italy and Spain – behind Barcelona forward Ansu Fati.
Telles scored 26 goals and made more than 50 assists for Porto after joining them from Galatasaray in 2016.
He said joining United, a club with “prestige”, was a “huge honour”.
“You have to work hard to get to this moment in your career and now I am coming to this club, I can promise that I will give everything in my heart to be a success here,” he added.
“I won many trophies at FC Porto and I want to continue that at United. The manager has a clear plan and direction for this team and I can’t wait to pull on the famous shirt.”
United manager Ole Gunnar Solskjaer said: “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 has the qualities, both as a player and as a person, that we want here at Manchester United.”
Telles is United’s second signing of the summer transfer window after the arrival of Netherlands midfielder Donny van de Beek from Ajax in September.
United are closing in on a deal to sign Uruguay striker Edinson Cavani, who is a free agent after leaving Paris St-Germain.
Defender Chris Smalling has left the club – completing a permanent move to Roma, where he spent last season on loan.
The England international has signed a three-year deal for a fee of 15m euros (£13.6m), rising to 20m euros (£18.1m) with add-ons.
Smalling played 323 times for United, winning two Premier League titles, one FA Cup, a League Cup and the Europa League.
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