Tranmere manager Ronnie Moore says Ben Gibson's loan spell from Middlesbrough could be ended early by injury.
The 19-year-old was but the centre-back is set for a prolonged spell out with an abductor problem.
Moore told BBC Radio Merseyside: "He's been to see a specialist and it looks as though he's out for six to eight weeks, which would be a nightmare.
"We'll have a chat to Ben and I'll speak to [Boro boss] Tony Mowbray."
But Moore has not ruled out the possibility of Gibson returning to Tranmere once he is back to full fitness.
He added: "We've got him until January, but he'll go back to get treatment and then we'll take it from there."
Gibson's only appearance for Middlesbrough came as a substitute in April 2011 and he had loan spells at Plymouth and York last season.
He has excelled at the heart of the Tranmere defence since playing 25 times for the League One leaders.