Marcos Rojo insists he has joined Manchester United to work hard with his new team-mates to win trophies at Old Trafford.
Louis van Gaal made a move to strengthen his much-maligned defence after completing the signing of the Argentina international from Sporting Lisbon.
The 24-year-old moved to Old Trafford on a five-year deal for a fee of £15.98million, with winger Nani moving in the opposite direction on a season-long loan, and his ability to play left-back or centre-half will come as a blessing to Van Gaal as he beds in his new 3-5-2 formation.
The Manchester United boss saw centre-backs Rio Ferdinand and Nemanja Vidic walk out of the door at Old Trafford this summer alongside left-back Patrice Evra with only Luke Shaw arriving from Southampton as a replacement.
Rookie Tyler Blackett was deployed alongside Phil Jones and Chris Smalling in central defence as United lost their Barclays Premier League opener against Swansea 2-1 on Saturday with Jesse Lingard making his first top-flight start at wing-back.
That defeat exposed United's frailties at the back and Van Gaal is delighted to have secured the services of a player who has 28 caps for his country.
"Marcos is a very gifted defender," he said. "He has played at the highest level in world football and can play either as a central-defender or left-back.
"He has ability, physical strength and a willingness to learn that means he has a very bright future ahead of him.
"He had a very strong World Cup and has been playing in Europe for a couple of years now. He is a very good addition to the team."
Rojo began his career in his homeland with Estudiantes de la Plata and spent a single season with Spartak Moscow before moving to Sporting in 2012.
He played all 120 minutes of July's World Cup final as Argentina lost to Germany after extra-time in Rio de Janeiro and cannot wait to play his part in Van Gaal's new era at United..
"It is such an honour to say that I now play for Manchester United," he said. "The Premier League is the most exciting league in the world and to have the chance to play in it for the world's biggest club is a dream for me.
"I am young and am very keen to continue to learn the game, so playing for such an experienced technical coach as Louis van Gaal is a fantastic opportunity for me.
"I have joined United to work hard with my team-mates to win trophies and I know that the manager shares that ambition."
The move for Rojo had been complicated by a row between Sporting and a third-party ownership group, while the player upset his employers by initially refusing to train in a bid to push through the deal, although he later apologised and returned to work.
The 27-year-old Nani, who moved to Manchester seven years ago, previously spent four years as a Sporting player after leaving Real Massama in 2003.
He has made 228 appearances in all competitions for United, scoring 40 goals, but has rarely been a regular starter during his time in the Premier League.