The former England and Manchester United captain landed in the UK on Tuesday for further talks with the Championship side about a deal to become a player-coach.
Rooney is currently plying his trade in the United States with DC United, where he was recently named captain, and is contracted to the club until 2021.
But he is keen to return to England and is now poised to end his contract with DC United early.
Rooney could well leave at the end of the current MLS season, which finishes in November, with Derby keen for him to join in January.
Derby appointed Phillip Cocu as manager on a four-year contract earlier this summer after Frank Lampard left his post at the club to take over at Chelsea.
Speaking about the rumours Rooney could join his staff, Cocu said: “I can’t say anything about that – we’re working hard to complete the team and we always try to find the best player in a certain position.
“In the world of football, we cannot speak before it is signed.”