Berardi spent seven years at Leeds and was a fan-favourite at Elland Road because of his all-action style of play.
Towards the end of his time at Leeds he struggled with injuries and even made the admission that the Whites need to have better players than him in the squad.
Following his emotional farewell in 2021, he spent the rest of his career in his native Switzerland at FC Sion before ending his career at the end of this season at AC Bellinzona.
Redfearn managed Berardi at Leeds when both were at Elland Road and admitted that the defender has the heart of a lion.
He thanked the defender for showing faith in him and is hopeful that his retirement will be a happy one.
The former Leeds boss took to Twitter and wrote: “Good luck in your retirement my friend, heart of a lion!
“I’ll never forget your trust and friendship and belief in what was right.
“You deserve the best.”
Marcelo Bielsa did allow Berardi to play twice in the Premier League before he eventually left the club.