Manchester United have made Victor Lindelof their first signing of the summer after the Sweden defender signed a four-year deal on Wednesday.
United paid Benfica 35million euros (£30.75million) for Lindelof, although the Portuguese club announced that the fee could increase by a further 10million euros due to add-ons.
United boss Jose Mourinho told the club's official website: "Victor is a very talented young player, who has a great future ahead of him at United.
"Our season last year showed us that we need options and quality to add depth to the squad and Victor is the first to join us this summer.
"I know that our fantastic group of players will welcome him as one of us."
Lindelof arrived at United's Aon Training Complex fresh from international duty with Sweden, where he was an unused substitute in Tuesday night's 1-1 draw with Norway.
Lindelof has been a long-time target for United as they look to bolster their defensive options ahead of next season's return to the Champions League.
He told United's official website: "I am thrilled to be joining Manchester United.
"I have enjoyed my time at Benfica enormously and I have learned a lot there. But I'm looking forward to playing in the Premier League at Old Trafford and for Jose Mourinho.
"I'm keen to get started and make my contribution to the team's efforts to win more trophies."
Lindelof could be one of three or four high-profile acquisitions at Old Trafford this summer, with the club also understood to be keen on Alvaro Morata.
The Real Madrid forward's agent said earlier this week that United had lodged a "very important offer" with the Spanish giants to try to bring him to the north west of England.
In defence, Mourinho now boasts an impressive array of options with Lindelof joining the likes of Eric Bailly, Marcos Rojo, Chris Smalling, Phil Jones and Daley Blind.
But Lindelof, who started his career with lowly Swedish club Vasteras before moving to Benfica in 2011, said he is willing to fight for his starting place.
In an interview with MUTV, Lindelof said: "Of course there are some great players here in my position.
"I'm here to do my best to try to help the team as much as I can and it's always good to have other good players around you. When you have that, you get better as well.
"I think every move means you have to adapt to a new environment but I feel comfortable in myself. I trust myself and it's going to be tough but I'm looking forward to it.
"I always had a dream of coming here to play in the Premier League so, for me, it's a dream come true."
