Alexis Sanchez faces a race against time to be fit for Manchester United's clash with Tottenham Hotspur next Monday.
Chile international Sanchez missed the 3-2 defeat at Brighton on Sunday after picking up a muscle injury in training on Friday, although sources have told ESPN FC the problem is considered minor.
But with just seven days to prepare for Tottenham's visit to Old Trafford, the 29-year-old -- who will undergo further tests this week -- has a battle to be fit.
It means manager Jose Mourinho faces the prospect of lining up for United's first head-to-head against a top-six opponent without a star man as they look to bounce back from the demoralising result at the Amex Stadium.
Sources have also told ESPN FC that Luke Shaw will be assessed this week after picking up two knocks to his left foot against Brighton.
The left-back was involved in clashes either side of half-time and, despite being able to complete the 90 minutes, will be managed carefully to ensure he is fit to face Spurs.
Mourinho should be able to welcome back Nemanja Matic and Antonio Valencia against Mauricio Pochettino's side. Both have returned to training following abdominal and calf problems respectively, but were not deemed fit enough to make the trip to Brighton.
Ander Herrera was back in the squad after injury but Sergio Romero, Marcos Rojo and Diogo Dalot remain sidelined.