Motherwell goalkeeper Trevor Carson needs surgery after suffering a serious knee injury and will be out until at least February.
The Northern Ireland international was replaced during Saturday's Scottish Premiership win over Ross County.
Carson, 32, missed most of the 2018/19 campaign with deep vein thrombosis.
Motherwell said he will be out for "a minimum of three months" but a more accurate timescale will only become clear after he is operated on.
"It is a blow," said manager Stephen Robinson, who is considering whether to sign a replacement.
"He has done so well since he's got back into the side and also getting back into the national team.