Harford had a spell in caretaker charge at the City Ground last season following Joe Kinnear's exit and threw his hat into the ring to replace Kinnear on a permanent basis.
He lost out to Gary Megson though and left the club. A short time later he was named as the new Rotherham manager, with the Millers all but doomed to relegation from the Championship.
A bright start to the current season was followed by a 17-match run without a win and Harford was sacked after Saturday's 2-1 defeat by Yeovil.
Elsewhere, former Forest striker Jean-Claude Darcheville is set for a return to British football.
The Bordeaux man is wanted by Glasgow Rangers according to reports.
Darcheville made 19 appearances for the Reds in the 1998/99 season, scoring 2 goals.