Robertson is leaving League One club Blackpool this summer and will become a free agent.
It has been reported that Sunderland, who will play in League One next season after getting relegated from the Championship, have made contact with the 24-year-old central defender.
The Sunderland Echo has also claimed that new Black Cats’ manager Jack Ross wanted to sign the centre-back when he was in charge of St. Mirren in Scotland.
According to Sky Sports, Wigan Athletic, Blackburn Rovers and Bolton Wanderers are interested in signing Robertson on a free transfer this summer.
The Sunderland Echo has claimed that the former Aberdeen centre-back wants to test himself in the Championship.
Robertson has proved himself at the League One level, and Sunderland need players like him in order to bounce straight back to the Championship.
Given that the former Aberdeen centre-back is a free agent, it would be quite a coup from the Black Cats if they are able to secure his services ahead of Wigan.