Sheffield United manager Kevin Blackwell fears Nick Montgomery has suffered a serious knee injury.
The Blades are concerned that the midfielder has sustained ligament damage, which would add to the Championship outfit's fitness problems.
Blackwell has his fingers crossed that Montgomery's setback is not too serious, but he confesses that he is worried.
The United boss said: "Monty's done his knee. We're not sure about the severity of it, but it doesn't look good.
"His knee is in a brace. He was running one way and his knee got knocked the other side and he said his knee felt all wobbly and loose just before half-time.
"So it's not a good sign. Please God it's not what we think it is."