United have signed Torino and Italy defender Matteo Darmian for an undisclosed fee, thought to be in the region of £12 million.
The 25-year-old Italian international has signed a four-year deal at Old Trafford, with the club having the option of a further year.
"To work with Louis van Gaal, a manager that has achieved so much in football, is such an exciting prospect.
"When a club like Manchester United show interest, you can't turn them down" said Darmian.
He has made 146 appearances for Torino since his debut in 2011 and he also has 13 international caps, including a start in all three of Italy's World Cup matches in Brazil last summer.
"Matteo is a right-sided full back with the versatility of being able to play on the left" said United boss Van Gaal.
"He is a strong defender and he has the ability to go forward in the attacking positions which is a fantastic attribute to have and much needed in the fast rhythm of the Premier League."
Darmian's signing follows confirmation that a deal has been agreed with Bayern Munich for midfielder Bastian Schweinsteiger to move to Old Trafford.
He is expected to join up with LVG's side as they leave for the pre-season tour to the USA on Monday.