Jamie Carragher, Dietmar Hamann and Michael Owen were are among those to pay tribute to Gerard Houllier on Monday after he died at the age of 73.
The former Liverpool, Paris Saint-Germain and France manager passed away after recently undergoing heart surgery.
Houllier was an assistant with Les Bleus before taking the top job in 1992 and left the post the following year after failing to qualify for the 1994 World Cup.
The French Football Federation tweeted: "The @FFF would like to express its deepest condolences to the family and friends of Gerard Houllier, former coach of the French national team and DTN (National Technical Director), who passed away at the age of 73."
He is perhaps best remembered for his spell in charge of Liverpool, having steered the club to five trophies - including an FA Cup, League Cup and UEFA Cup treble in the 2000-01 season.
Owen was leading scorer for Liverpool during that hugely successful campaign, one that climaxed with Houllier's side sealing third place in the English top flight and thereby qualifying for the Champions League.
"Absolutely heartbroken to hear that my old boss, Gerard Houllier, has sadly passed away. A great manager and a genuinely caring man," the former England international wrote on Twitter.
Carragher was also a regular in 2000-01, having come through into the first team under the Frenchman's guidance.
The one-club man - who sits second on the all-time list of appearances for Liverpool - thanked Houllier for the impact he had on his career, revealing they had only recently spoken to each other with regards a visit to the city again.
"Absolutely devastated by the news about Gerard Houllier, I was in touch with him only last month to arrange him coming to Liverpool," Carragher tweeted.
"Loved that man to bits, he changed me as a person and as a player and got Liverpool back winning trophies."
Hamann, who was signed by Houllier, used Instagram to share his condolences following the news, posting a picture of his old boss holding the UEFA Cup trophy in the aftermath of the stunning 5-4 victory over Deportivo Alaves in Dortmund.
"Devastated to hear the news that our former manager Gerard Houllier passed away. Great manager and an even better man. You'll never walk alone Gerard," Hamann wrote.
Sami Hyypia, another key signing during Houllier's successful spell on Merseyside, fondly remembered "an absolute gentleman", who had an impact not just on his career on the pitch.
"Sad to hear Gerard Houllier passed away. Football world has lost an absolute gentleman and lover of the sport today! The man, who had faith in me to bring me to Liverpool and gave me confidence to become who I am right now, is no longer with us. Lot of strength to his family," the former Finland defender - who spent over a decade at Liverpool - posted on Instagram.
Liverpool legend Ian Rush tweeted Houllier was a "true gentleman of the game" who "always put others first", while England legend Gary Lineker described him as "one of the smartest, warmest and loveliest people".
Houllier left Liverpool in 2004, replaced by Rafa Benitez, and went on to manage Lyon and Aston Villa, where the Frenchman stepped down by mutual consent due to health issues after a solitary season in charge.
"All at Aston Villa are deeply saddened to learn of the passing of Gerard Houllier, our manager during the 2010/11 season," Villa said on Twitter, along with a picture of Houllier during his time in charge. "Our thoughts are with Gerard's loved ones at this incredibly difficult time."
All at Aston Villa are deeply saddened to learn of the passing of Gérard Houllier, our manager during the 2010/11 season.— Aston Villa (@AVFCOfficial) December 14, 2020
Our thoughts are with Gérard's loved ones at this incredibly difficult time.
Houllier also worked with FIFA, providing "invaluable input" while serving on the organisation's technical committee.
FIFA posted: "We are saddened to learn of the passing of Gerard Houllier. Besides his outstanding work with the likes of Liverpool, Lyon and France's national team, Gerard provided invaluable input to FIFA's technical study group."