Meanwhile, the Bees head into Wednesday's encounter at their new ground having put together a nine-match unbeaten streak in the Championship.
Having avoided defeat since October 24, you would be forgiven for thinking that Thomas Frank and his Brentford squad will be full of smiles when heading into training this week.
However, a 2-2 draw at home to Blackburn Rovers, opposition who played with 10 men from the 36th minute, has left the Bees with a feeling of underachievement, both in the short and long term.
As well as dealing with the disappointment of Saturday's result, Brentford have barely moved up the standings with a nine-match unbeaten run which has included just four wins.
While just a four-point gap separates the London outfit and leaders Norwich City, Frank requires something extra from his side, particularly in the final third of the pitch.
Overcoming Derby would represent a fourth win in five outings, and there is a feeling that is what is required to keep the team heading in the right direction.
The Rams make their second trip to London in quick succession after battling their way to a narrow triumph over Millwall at the weekend.
Although Rooney will not get carried away with the success at The Den, the result moves Derby to within two points of 20th position, lofty heights when considering that they have spent almost the entire season in the bottom three.
Rooney will be realistic about his team's chances on Wednesday night, but being clear underdogs may suit a team who are looking to play with more freedom under their new interim boss.
Brentford Championship form: DDWWWD
Derby County Championship form: LLLDDW
The extra day of recovery may lead to Rooney naming an unchanged Derby XI for this game.
Brentford possible starting lineup:
Raya; Dalsgaard, Pinnock, Jansson, Henry; Dasilva, Jensen, Janelt; Canos, Toney, Mbuemo
Derby County possible starting lineup:
Marshall; Byrne, Davies, Clarke, Forsyth; Bird, Bielik; Jozwiak, Knight, Waghorn; Kazim-Richards
We say: Brentford 3-1 Derby County
While Derby will undoubtedly be on a high after their success at the weekend, Brentford will be motivated to put things right after dropping two points against Blackburn. With that in mind, expect the Bees to be more ruthless than in previous games, particularly against opponents who may set up looking for a draw.