Derby County captain Richard Keogh has been sidelined for a month with a knee injury.
The defender suffered medial ligament damage on Saturday during his side's 3-1 win at home to Doncaster Rovers in the Championship.
Keogh, 27, is expected to return to action for the Rams by the end of January 2014.
Derby continue their Championship campaign on Boxing Day when they travel to Huddersfield Town.