Sunderland striker Andrew Nelson is set to miss the rest of the season.
The teenager suffered a knee injury playing for loan club Hartlepool United at the weekend.
Nelson, 19, suffered damage to his medial ligaments after coming off the bench late in Saturday's game against Plymouth Argyle.
Hartlepool’s head physio Ian Gallagher said: “The scan confirmed our worst fears.
“Andrew has now returned to Sunderland for treatment, but the nature of the injury means it’s doubtful that he will be able to play again this season.”
Nelson joined Hartlepool in last month's transfer window.