Newcastle fear striker Sammy Ameobi is facing several months of rehabilitation after suffering an unconfirmed injury.
The England Under 21 international sustained the problem in the Premier League club's reserve-team win over Wigan on Tuesday.
Ameobi, 19, was forced off as a result of a challenge in the match and is now expected to be out of action for a 'number of months'.
The forward has made a total of 13 appearances for Newcastle so far this season - 12 of them from the bench.
Newcastle said in a statement on their official website: "Sammy Ameobi will be sidelined for a period of time, likely to be a number of months, as a result of an injury sustained in the reserves' win over Wigan."
The fitness setback is another reason Newcastle manager Alan Pardew could consider an attempt to sign a striker in January amid resurfacing reports of interest in Paris Saint Germain's Turkish international, Mevlut Erding.
Pardew is already without star man Demba Ba during the early weeks of 2012 due to the Senegal international's African Cup of Nations commitments.