Southampton manager Nigel Adkins has revealed that Richard Chaplow will be sidelined for a few weeks due to a knee problem.
Chaplow had been hoping to be fit very soon after returning to full training, but suffered a setback ahead of Friday's home game against Bristol City.
Adkins has now confirmed that the midfielder will not be back in action for some time, and admitted it is a blow to lose such a key man.
Adkins told Saints' official website: "Unfortunately Richard has had a setback in his recovery.
"He was back in full training the other day and looking great guns but he slipped in the turf and opened his knee joints a little bit so that is a bit of a setback, but I'm sure he will come back stronger than ever.
"He will be out for a few weeks, it's a shame as he was really close and back in training with the rest of the group, but the ground gave way underneath him two days ago and it's a setback for him and us.
"He has worked really hard to get back into contention so it is a shame."
Southampton, who have a three-point advantage at the top of the table, ended a run of three games without a success with a 2-0 home defeat of Crystal Palace on Boxing Day.
Widely-travelled striker David Connolly came off the bench to figure in the victory and could be pushing for a start again against Bristol City.