Wayne Rooney guided Derby through a tumultuous season last time out but left the job this summer, leaving Liam Rosenior in interim charge.
Derby are sitting just outside of the playoffs places in the League One table, and could still go for a permanent manager to take over from Rosenior.
Warne has been linked with possibly departing the Rotherham job and one of his suitors are claimed to be Huddersfield Town.
Derby are also keeping tabs on Warne though and should they wish to make a change, he will be on a list of targets for the Rams.
The Rams are looking to bounce back to the Championship at the first attempt and Warne has guided Rotherham out of the third division no fewer than three times.
However, it remains to be seen if he is willing to step down from the Championship to League One, especially with Huddersfield also interested.
Warne has only ever managed Rotherham in his time in football management, having been there since 2016.
