Perrin prepares to return to Lyon for derby
Perrin was sacked by Lyon last June despite leading them to a record seventh successive title and their first domestic double.
"To be sacked is part of the job and I'll go back to Lyon without resentment but it will be a special occasion," he told reporters.
Matches between the two arch-rivals are regarded by their supporters as the most important of the season.
St Etienne overshadowed the club of France's second city in the 1960s and 1970s when they claimed a record 10 titles. But they then faded away and only climbed back to the top flight in 2004 just as Lyon were fast becoming the Ligue 1 superpower.
The French champions have won seven of the last nine derbies with the other two drawn. St Etienne are 17th in the standings, three points clear of the drop zone.
Lyon's lead at the top has been cut to one point by Girondins Bordeaux after three successive draws at home.
"We are losing too many points at home. We must re-establish our domination," playmaker Juninho was quoted as saying after they were held 1-1 by midtable Lorient earlier this month.
Lyon's title rivals also play on Sunday. Bordeaux, on a run of seven games without defeat, host seventh-placed Lille while third-placed Olympique Marseille, four points behind Lyon, travel to lowly Sochaux.