The Rams currently sit 21st in the Championship table, four points above 22nd placed Rotherham, but the Millers have two games in hand.
Derby have now lost their last four games on the spin and suffered a 3-0 drubbing at Preston North End earlier this week, and Rooney will hope for a turnaround soon.
Rooney highlighted that a major cause of concern is his team’s inability to find the back of the net enough while conceding sloppy goals.
The former striker conceded that Derby have made the job difficult for themselves and much will depend upon results of other teams in terms of their survival in the Championship.
Speaking to BBC Radio Derby, Rooney said: “We are conceding too many sloppy goals and yet again a few half-chances for us, but we don’t score.
“We have given ourselves an uphill battle in the next three games.
“We have to hope that other teams lose and we have to try and win our games to give ourselves a chance of staying in the league.”
Derby are next in action at home against Birmingham City, while then they will have two games to play, against Swansea City and Sheffield Wednesday.