The legendary Scotsman announced his retirement from his current position on Wednesday after almost three decades in charge at Old Trafford and Sergio Busquets is amazed by his longevity.
"His retirement is a loss for the football world. All the things he won and that he always stayed at the level of the best coaches is amazing."
Barca full-back Daniel Alves is another to shower praise on the two-time Champions League-winning coach and believes the Scot has set an example for everybody else to follow in his career.
"[His retirement is like] removing a myth of football," the Brazilian said on Twitter. "He is the kind of professional that helps make this occupation meaningful! Thanks Sir Alex Ferguson."
Fellow Camp Nou star Cristian Tello added on his Twitter profile: "All my admiration for Sir Alex Ferguson. He leaves the bench for Manchester United after 26 seasons. Legend."
Goal.com exclusively revealed in the wake of the announcement that Everton manager David Moyes will replace Sir Alex, with a club announcement expected imminently.
The Scot won 13 league titles with United, five FA Cups and two Champions Leagues.