Tottenham Hotspur, Chelsea and Arsenal have all dropped points during the run-in, but it is United's slump which has been the most dramatic with seven defeats from their last nine games across all competitions - their worst run of form since 1962.
Wednesday's derby loss to Manchester City left them still three points adrift of fourth-placed Chelsea, and anything other than a victory this weekend over the team they are trying to catch would leave them facing the prospect of Europa League football next season.
Here, Sports Mole looks at how Ole Gunnar Solskjaer could set his side up as he looks to stop the rot.
Solskjaer has confirmed that David de Gea's status as number one is not under threat despite an error-strewn campaign by his usual standards, including mistakes for both goals in Wednesday's derby.
United played with five at the back for the visit of Man City, but they are unlikely to be as defensive against Chelsea and could revert to a 4-3-1-2 formation - although Solskjaer does seem to still be looking for his preferred system.
Nemanja Matic was among the players dropped against City following the horror-show at Everton last weekend, but he will hope to regain his place with Fred's recent performances having also drawn criticism.
United could be boosted by the return of Ander Herrera after six games out with a hamstring injury, while Romelu Lukaku is also pushing for a recall alongside Marcus Rashford as Solskjaer tries to boost his side's attacking threat.
The Red Devils have failed to score a single goal from open play in their last five matches, with their only strikes in that time coming from the penalty spot courtesy of surprise PFA Team of the Year inclusion Paul Pogba.
Phil Jones, Eric Bailly and Scott McTominay remain doubtful, with the latter having failed a fitness test ahead of the derby and undergoing another one prior to Sunday's match.