But which players are still available this summer who could be interesting the Black Cats? We take a look at the best players still available who could realistically arrive at the Stadium of Light in the coming weeks – scroll down and click through the pages to see who could be available as transfer business ramps up:
13. Jon Taylor (Free Agent)
The wideman is eyeing a move to the Championship despite rumoured interest from the Black Cats, but a deal could yet happen as the window drags on.
Photo: Nigel Roddis
14. Jason Pearce (Charlton Athletic)
Heavily linked with Sunderland and others throughout the window, the experienced Pearce could yet be allowed to leave the Valley - and any deal could help Ross address his defensive issues.
Photo: Pete Norton
15. Harry Brockbank (Free Agent)
The versatile defender is in high-demand following his exit from Bolton Wanderers and would provide some much-needed cover for the Black Cats.
Photo: Marie Caley
16. Daryl Murphy (Nottingham Forest)
Transfer-listed by Nottingham Forest, the experienced striker looks set for a summer move. Could a Stadium of Light switch be on the cards?
Photo: ADRIAN DENNIS