Former Manchester United manager Sir Alex Ferguson is fighting for his life after undergoing an emergency surgery following a brain hemorrhage. United confirmed on Saturday that the 76-year-old fell ill on Friday and has been in intensive care since going under the knife.

In a brief statement, the Manchester-based club, where Ferguson served for more than 26 years as the manager, said: “The procedure has gone very well but he needs a period of intensive care to aid his recovery. His family request privacy in this matter. Everyone at Manchester United sends our very best wishes.”

Often regarded as the best manager in English club football since Liverpool's legendary Bill Shankly and Matt Busby, who managed Manchester United between 1945 and 1969, Ferguson said goodbye to his role at the helm of the Red Devils in 2013, after leading his side to an incredible 38 trophies.

The Scot, who had a rather inconspicuous and insignificant career as a forward for several local clubs, including Dunfermline Athletic and Rangers, had joined a struggling United as a manager from Aberdeen Football Club after helping them break the Celtic and Rangers dominance of Scottish football in November 1986.

Since then he not only revived United’s dwindling fortune but also catapulted them to the perch of English as well as European football with 13 Premier League titles, 5 FA Cups and two Champions League titles coming to Old Trafford’s glittering trophy cabinet. During his glorious days in United, he made two phrases, “hairdryer treatment” and “squeaky-bum time,” popular and his uncompromising style of management motivated United players to clinch victories or draws from the jaws of defeat – often in the dying moments of the game, popularizing another phrase in the process: "Fergie time."

After he bid farewell to coaching at the end of the 2012–13 season, having won the Premier League in his final season, Ferguson not only guided United’s management on several key decisions but also became a public speaker on management and a brand ambassador of the game.

His last public appearance was when he presented Arsenal manager Arsene Wenger with a commemorative trophy before the United's 2-1 victory over the Gunners last Sunday.

On Saturday, speculations were rife about the 76-year-old's health after his son Darren Ferguson, the manager of Doncaster, did not attend his side's final match of the season against Wigan reportedly because of a “severe family issue.” Soon, many of Sir Alex' former proteges flooded the social media with their respective wishes for his speedy recovery.

Former United player David Beckham posted on Instagram: “Keep fighting Boss. Sending prayers and love to Cathy and the whole family.”

Cristiano Ronaldo, another talented superstar who was groomed and polished at Old Trafford under Ferguson’s wings, wrote on Twitter “My thoughts and prayers are with you, my dear friend. Be strong, Boss!”

Wayne Rooney, who was signed by Ferguson from Everton and went on to become United's all-time leading scorer, tweeted: “Get well soon Boss. Thoughts with all the family at this sad time.”

Meanwhile, the Football Association (FA), Premier League, FIFA, UEFA and several erstwhile rival clubs from Britain and around the world, including Manchester City and Liverpool, tweeted their best wishes for the iconic manager.