The 35-year-old returned to England in January after two years playing for MLS side D.C United in Washington and signed an 18-month contract with the Rams to become a player-coach.
Following Cocu’s sacking last week, Rooney was confirmed as part of a four-man coaching team which also includes Shay Given, Liam Rosenior and Justin Walker.
That quartet will oversee their first game in charge on Saturday at Bristol City with Derby rooted to the bottom of the Championship table with just one win from 11 games so far.
The club are on the brink of being taken over by United Arab Emirates businessman Sheikh Khaled bin Zayed al Nahyan and the new investors are, according to ESPN, reluctant to entrust Rooney with the job given his lack of experience and Derby’s perilous situation.
Rooney is yet to earn all of his coaching badges and with relegation an unthinkable scenario, Derby are likely to opt for a more experienced manager and have been linked with the services of Rafa Benitez this week.
Speaking about his determination to advance his coaching career, meanwhile, Rooney said earlier this week: ‘I wouldn’t be an ambitious person if I sat here and said I didn’t want the job,” Rooney told the media at a press conference.
‘I’ve made it quite clear over the last few years that my ambition is to go into management, especially when you see the likes of Steven Gerrard, Frank Lampard and Scott Parker all getting good jobs and doing really well at it.
‘We have to get the next two or three games out the way first, but if they go well it puts me in a better position to put our names forward for that role. We’re working together and if it works [as a group] it could be a way forward also.’