Derby defender Jake Buxton is likely to be out for the season, but they are hopeful top-scorer Chris Martin will return after the international break.
Buxton, 30, needs surgery on his back injury and is unlikely to feature in the Championship promotion push.
Martin, 26, has a hamstring problem and has not played since the game against Bournemouth on 10 February.
But first-team coach Paul Simpson is "hopeful" 19-goal Martin will be fit to face Watford on Friday, 3 April.
"We are still waiting on Chris," Simpson told BBC Radio Derby. "Jake could be out for up to eight weeks, so that is a blow."
The Rams have won just two of the nine league games since Martin was injured and have dropped to fifth in the table, six points adrift of leaders Bournemouth.