The Black Cats played seven matches in February and have looked jaded during three consecutive defeats against Rotherham, Coventry and Stoke.
Head coach Tony Mowbray has tried to rotate his team at times, but has highlighted a lack of options in certain positions.
So which Sunderland players have featured the most this season?
Here’s how many minutes each Black Cats player has racked up in all competitions:
So which Sunderland players have featured the most this season?
5. Niall Huggins - 150 minutes
It’s been a long road back for the 22-year-old full-back who has made two senior appearances after a lengthy injury setback. Photo: FRANK REID
6. Alex Bass - 195 minutes
Following his summer arrival from Portsmouth, the 24-year-old has made two senior appearances in cup competitions. Photo: Martin Swinney
7. Jewison Bennette - 293 minutes
The 18-year-old has made 14 league appearances off the bench, with his only senior start coming against Shrewsbury in the FA Cup. Photo: Frank Reid
8. Joe Gelhardt - 536 minutes
Since joining Sunderland on loan from Leeds in January the forward has started seven consecutive Championship fixtures. Photo: Frank Reid