Swansea City's on-loan defender Steven Caulker could be out for two months after suffering cartilage damage in his knee.
Caulker joined the Premier League new boys on a season-long deal from Tottenham Hotspur in the summer and has started all four of the club's games in the top flight.
However, during last weekend's 1-0 defeat at Arsenal, the 19-year-old twisted his knee when making a goal-line clearance and he will now return to Spurs for treatment.
A Swansea statement read: "A scan this week confirmed the injury and Caulker will return to White Hart Lane tomorrow to be assessed further by club specialists when a further update will follow."
The Swans are already without Alan Tate, who recently broke his leg in a golf buggy accident, although captain Garry Monk could be in line for a rapid return after stepping up his return from a foot injury.
Manager Brendan Rodgers, who returned to training on Thursday following the death of his father, has also not been helped by the delay in receiving international clearance for deadline day signings Darnel Situ and Rafik Halliche, leaving him short of options at the back.
Midfielder Kemy Agustien, who had been identified as a possible solution to the defensive shortage, is also out after suffering a hamstring injury against Arsenal.
But midfielder Wayne Routledge is back in training after missing out at the Emirates Stadium with an ankle problem.