"This is probably the biggest day of my rugby career, it's not everyday you play in a European final. I will definitely savour the moment," he said.
Ferris is enjoying an unexpected spell in the limelight. Tipped by no-one to progress to the final, Caerphilly have cut loose all their domestic problems and found the PARKER PEN SHIELD a welcome relief from the political restructuring in the Welsh game.
"Caerphilly have done so well in Europe this year, and it's because there has been less pressure than playing in the Welsh league," Ferris said.
"The boys have been able to express themselves. We have taken every game as it comes. "The most important game in our progression to the final was the semi-final first leg against Petrarca Padova. The boys came away with a cracking win away from home, which really took the pressure off. People started talking about reaching the final then.
"We know Castres are in a rebuilding phase, but we also know they are a top-class processional outfit, and we will have to be at our best to beat them.
"However, if we start with the passion and pride that the Welsh teams have shown against the French sides in the past, then we could ruffle their feather and disrupt their game plan and play some good rugby to win the game."
Team manager Christian Gajean: "This is a big adventure for us and a great opportunity. We're building for the future and it would be great to win a title.
"We didn't have a great championship season but we're still in the top flight in France. We were in the semi-finals of the Heineken Cup last year but we have had many player movements. We've changed a lot of our staff and we're still looking for other players.
"We hope to be at a higher level in three seasons' time and winning a European title would be a great starting point for us."
Gajean has particular reason to relish the game against Caerphilly because the Welsh club was the venue for his first international rugby experience on a school exchange trip when he was living in Paris. "I still remember that trip to Wales when I was a teenager. It was a great experience and now I find myself in charge of a team playing against them in a European final."