The Black Cats have already brought in four new faces, with Carl Winchester, Jake Vokins, Jordan Jones and Ross Stewart having all put pen to paper on Wearside.
But there may yet be further movement on deadline day, with some outgoings potentially set to be sanctioned.
So what will Sunderland’s best XI look like when the window closes at 11pm tonight?
Assuming Lee Johnson gets his transfer wish – and the Black Cats are able to keep hold of their prized assets – there will be some key dilemmas across the pitch.
We’ve taken a guess at how the Wearsiders’ new-look side could shape-up moving forward below – with places for all of the new signings.
What do you think is now Sunderland's best starting line-up? Tweet us on @sunechosafc and let us know!
1. GK: Lee Burge
Burge has established himself as Sunderland's number one since the arrival of Lee Johnson and, despite some shaky moments across the campaign, he looks set to retain his starting place for the foreseeable future. Photo: FRANK REID 2020
2. RB: Max Power
The Black Cats' skipper has impressed since making the switch to right-back and looks set to continue in that position moving forward - with his delivery from wide areas a major asset for Sunderland in the final third. Photo: FRANK REID 2020
3. CB: Bailey Wright
Wright's absence was certainly felt in Sunderland's draw with Gillingham at the weekend, and he's expected to return to the back four for the club's next league outing - having established himself as a star man this season. Photo: FRANK REID 2019
4. CB: Jordan Willis
The ex-Coventry City man has been a top performer since his return from injury and, while that will have to be carefully managed through the rest of the campaign, he will no doubt form a key part of Sunderland's backline as the season progresses. Photo: Frank Reid