The match was due to be played on February 14th but Derby's progression in the FA Cup means they are playing Man Utd that weekend.
The trip to Pride Park will now take place on Tuesday April 21st, ko 7:45pm.
The away game at Doncaster, postponed last Tuesday because of Doncaster's FA Cup involvement, will now be played on Tuesday March 17th. Kick off at the Keepmoat Stadium 7:45pm.