But with so many injuries hampering United's campaign last season, who will the 22-year-old's partner at the back?
His performances under Louis van Gaal were promising, and it appeared United had a long-term successor to Rio Ferdinand in their ranks.
But his progress has stagnated and with the incoming of Lindelof, Smalling could see his game-time greatly reduced next year.
Barring the odd rash challenge, Rojo had a stellar season last year and was one of the manager's most trusty soldiers at the back.
He cut out the flamboyant ball-playing and dangerous passing around the box and solely focused on his defensive duties, which improved his game to no end.
This one, reading “Go Where Your Food Is From,” was designed by illustrator Hide Your Toys.
W K tells Ad Freak that the campaign was inspired by how prominent travel pics are on dating profiles.If United opt for a back-three he is the perfect man to slot in on the left-hand side — as is Rojo.But also as an out-and-out left-back he has his merits, especially with Luke Shaw's United career hovering in a difficult place.The ultimate utility man at the back — which Mourinho likes for his fluid formations in defence.Although Blind has alluded to centre back being his preferred role, Mourinho will hope to deploy him as and when needed.Able to play at left back, a problem for United at present, Rojo's place as back-up to the preferred Bailly-Lindelof pairing is firmly cemented next year. Six potential centre backs at Old Trafford does not seem likely come the end of the transfer window but Jones has insisted he is not threatened by the Swede's arrival.