And with the transfer window now officially open, speculation is rife as to who the Black Cats could sign during the window.
Here, we take a look at the free agent options available to Lee Johnson during the window as Sunderland target promotion next campaign.
1. David Nugent
The 36-year-old prolific attacker is available on a free having left Preston North End. Although approaching the end of his career, Nugent could present an interesting short-term option for Sunderland in League One. Photo: Alex Davidson
2. Barrie McKay
The 26-year-old attacker - who spent last season on loan at League One club Fleetwood Town - is available for nothing this summer after Swansea City released him. Photo: James Chance
3. Sone Aluko
The 32-year-old former Hull City, Fulham and Rangers attacker is a free agent this summer after his release from Reading. Photo: Richard Heathcote
4. Nathaniel Mendez-Laing
The former Cardiff City attacker has just been released by Middlesbrough. Mendez-Laing, 29, may have offers from clubs higher up the pyramid though. Photo: Dan Istitene