Although neither club have yet confirmed the deal has gone through, BBC sport reports the World Cup star has told the Argentine media that he is delighted to have joined United.
"It's a dream to play at Manchester United and I am very proud of having the chance of working with [Louis] van Gaal," Rojo said in an interview with Argentinian radio station Continental.
"I have always liked English football, and I should adapt to this new playing style easily."
"I spoke with Juan
Sebastian Veron about Manchester United when we were at Estudiantes. I have
always liked English football, and I should adapt to this new playing style
easily."
The clubs are still in talks, however, and reports suggest Nani could be loaned out to Sporting as part of the deal.