The arrival of Lee Johnson had helped the Black Cats climb the table, but recent results have seen them lose ground on Peterborough United and Hull City who are now heavy favourites to seal a spot in the Championship next season.
And back-to-back defeats to Charlton and Wigan have seen hopes of a top two finish fade – ahead of some key fixtures against the likes of Blackpool and Hull City in coming weeks.
But with the battle for the top two still very much open, who are the bookmakers tipping for promotion come the end of the season?
We take a look at who League One title sponsors SkyBet believe will gain promotion this season, and how Sunderland’s odds have shifted in recent weeks.
All odds are correct as of Thursday, April 15.
1. Shrewsbury Town
Well, it's still mathematically possible! The Shrews may have been heavily beaten in midweek but have secured some eye-catching results this year. Current League One promotion odds: 2000/1 Photo: Pete Norton
2. MK Dons
Can Will Grigg help mount a late surge into the play-offs? The bookies aren't too confident. Current League One promotion odds: 2000/1 Photo: Naomi Baker
3. Crewe Alexandra
Another side with slight hopes of reaching the play-offs, Crewe were as short as 12/1 to gain promotion at some points in the campaign. Current League One promotion odds: 750/1 Photo: Charlotte Tattersall
4. Accrington Stanley
As short as 18/1 at some points during the campaign, Accrington's odds have lengthened after some disappointing results of late. Current League One promotion odds: 500/1 Photo: Jan Kruger