Manchester United defender Lisandro Martinez was stretchered off in the final 10 minutes of the 2-0 defeat to Crystal Palace at the weekend.
The Argentinian international suffered a knee injury and it is suspected that he damaged his anterior cruciate ligament.
That prognosis has not been confirmed by the club yet but, if the worst fears are realised, Martinez could be out for a considerable period of time.
Fans will be keeping their fingers crossed that the injury is not as bad as it first appears.