Rooney is striving to keep Derby in the Championship after a tumultuous season.
According to Football Insider, if they stay in the division, Rooney will target the 29-year-old.
Duffy spent this season at Celtic on loan from Brighton and Hove Albion.
Given Brighton boss Graham Potter has no plans to integrate Duffy into his side next term, he is likely to be available for loan or a permanent deal.
Derby are currently 21st in the Championship and sit two points above the relegation places.