The Red Devils began to build some momentum before the international break with three successive victories - including a famous win away to Juventus in the Champions League - but they were outclassed by Manchester City in their most recent outing.
Here, Sports Mole looks at how United could line up against Palace as they try to close that gap.
Out: Luke Shaw (suspended)
Doubtful: Paul Pogba (thigh), Romelu Lukaku (hamstring), Anthony Martial (groin), Marcus Rashford (knock), Marouane Fellaini (groin), Diogo Dalot (knock), Eric Bailly (knock)
United have question marks over a number of key players heading into this match, but one player who will definitely miss out is Luke Shaw, who will serve a one-game ban having picked up five yellow cards this season.
Antonio Valencia appears to be out of favour with Mourinho at the moment, which means that Shaw's absence could open the door for Diogo Dalot to make his long-awaited Premier League debut, with Ashley Young switching to the left.
Paul Pogba missed the Manchester derby and pulled out of the France squad with a thigh problem, but club physios are thought to be hopeful that he will recover in time for Saturday's match.
United's injury worries deepened during the international break as Anthony Martial, Marouane Fellaini, Romelu Lukaku and Marcus Rashford all returned with injuries, but the quartet could be fit to feature in some capacity.
Lukaku's hamstring issue - coupled with his recent club form - may limit him to a place on the bench at best, though, while Alexis Sanchez will return later than most following his Chile duties and so could also be amongst the substitutes.