Manchester United attacker Matheus Cunha is not guaranteed to be available for Sunday's Premier League showdown with FA Cup holders Crystal Palace at Selhurst Park.
The Brazilian attacker was absent from Monday's 1-0 home loss to Everton as a result of a training-ground accident, which is now understood to have been a blow to the head.
If Cunha is following concussion protocols, the former Wolverhampton Wanderers forward should also be unavailable for the clash with the Eagles, although Ruben Amorim will give an update at his pre-match press conference on Friday afternoon.
The Portuguese placed his faith in Joshua Zirkzee for the clash with the Toffees, but after the Dutchman's ineffective display, a start for Mason Mount surely awaits if Cunha is ruled out again.
Mount being brought back into the first XI could shift Bryan Mbeumo into an auxiliary number nine role, as the former and Amad Diallo start as Amorim's two number 10s in the English capital.
The visiting boss is also likely to make an unenforced change further back, as Patrick Dorgu was also found wanting against Everton and could make way for Diogo Dalot, but Noussair Mazraoui should be retained despite coming off at half time on Monday.
The same goes for Casemiro and Bruno Fernandes in the middle of the pitch, while Leny Yoro, Matthijs de Ligt and Luke Shaw are currently in no danger of losing their places in the back three.
Benjamin Sesko (knee) and Harry Maguire (thigh) will play no part in this match for the Red Devils.
Manchester United possible starting lineup:
Lammens; Yoro, De Ligt, Shaw; Mazraoui, Casemiro, Fernandes, Dalot; Mount, Diallo; Mbeumo
> Click here to see how Palace could line up for this game