Newcastle United striker Sammy Ameobi could be ruled out for "a number of months", the club has confirmed.
The 19-year-old was forced off after 56 minutes during Tuesday night's 3-1 reserve-team victory against Wigan with an unspecified injury.
Ameobi, who signed a new three-and-a-half-year deal in November, has made 13 first-team appearances this term.
Injury is also likely to rule the teenager out of England Under-21s' fixture against Belgium next month.
The younger brother of Magpies striker Shola, he made his Premier League debut against Manchester City in November.
He scored his one and only goal for the club in a 2-1 Carling Cup second-round victory at Scunthorpe on 25 August.