Nottingham Forest have now sold their allocation of tickets for their fourth round FA Cup tie on 23 January.
The last batch or tickets went on sale on Wednesday morning and have now sold out - meaning the Reds will have almost 5,000 fans in away seats at Pride Park.
Forest beat Manchester City 3-0 and Derby clinched a 4-3 victory over non-league Forest Green to get to the fourth round.
The tie will see ex-Rams boss Billy Davies' first return to Pride Park.
The fixture between the two arch rivals also has added spice after the appointment of former Nottingham Forest player Nigel Clough as Derby manager.
In an earlier league meeting in November, the two sides had to share the points following a controversial 1-1 draw at Pride Park.
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