The 24-year-old defender had already confirmed that he would be moving to the Red Devils during an interview with Argentinian radio Continental and now the Portuguese club have confirmed the news on Twitter.
Da venda de Marcos Rojo para o Man.Utd, 9M€ irão para a construção do nosso Pavilhão. #SportingCP
— Sporting (@Sporting_CP) August 19, 2014
The 20-time English champions have also confirmed the news via Twitter.
The Argentina international, who has 28 caps to his name – is believed to have cost United around £16m. He will sign a five-year contract at Old Trafford, subject to a medical.
Rojo will be United’s third summer acquisition after Ander Herrera and Luke Shaw.