Warnock, 67, was previously in charge of both Leeds United and Sheffield United. He spent part of this season in temporary control of Queens Park Rangers after a short spell at Crystal Palace in 2014/15.
The Sheffield-born manager is thought to be interested in the position, especially on a fire-fighting basis as Rotherham seek to stay in the second-tier.
Warnock played for Rotherham between 1969 and 1971 and is still thought to have some affection for the club.
Both Paolo Di Canio and Crawley Town manager Mark Yates are interested in the role, as are Stuart Gray and Gary Megson.
Redfearn’s dismissal saw him become the shortest-serving manager in Rotherham history. His spell lasted for 120 days or just 21 games.