Derby County midfielder David Ozoh has had his season ended by a thigh injury.
The on-loan Crystal Palace teenager was carried off the Pride Park pitch on a stretcher on Saturday after being hurt in the last minute of normal time against Millwall, who then went on to score a 95th-minute winner.
He was making just his fifth appearance since returning to action after four months out with hamstring and quad muscle problems.
It was also his first appearance under head coach John Eustace, who says losing the 19-year-old is a "big blow to the group".