And head coach Lee Johnson has discussed the market as Sunderland attempt to bring in fresh faces.
Charlie Wyke has decided to move to Wigan Athletic whilst the Black Cats allowed Max Power, Remi Matthews, Grant Leadbitter, Dylan McFadzean, Chris Maguire and Josh Scowen to leave the club at the end of the season.
Luke O’Nien and Aiden McGeady have signed new deals on Wearside, however, whilst Denver Hume is still weighing up a contract extension.
"At the moment, a lot of clubs are internally assessing where they stand in terms of their long-term future off the back of Covid-19," said Johnson.
"A lot of clubs are under soft embargoes, have taken out loans that have to be paid back.
"That's stagnated the market a bit, because you can't really do one in, one out.
"I've mentioned about agents who have been unrealistic, free agents are sort of seen as their golden goose and actually that's not true because the first thing clubs want to save is on agent fees."
Here, though, we take a look at all of the latest Sunderland-related and League One talk ahead of a busy window: