Former Manchester United coach Alex Ferguson, one of the greatest managers in football history, had surgery Saturday for a brain hemorrhage, according to a tweet from the team's verified Twitter account.
"Sir Alex Ferguson has undergone surgery today for a brain haemorrhage," the English soccer team 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."
United captain Michael Carrick tweeted that he was devastated to hear his former coach was in the hospital.
"All my thoughts and prayers are with him and his family. Be strong Boss," he wrote.
Liverpool, one of United's fiercest rivals during Ferguson's 26-year reign, sent its support.
"A great rival but also a great friend who supported this club during its most difficult time (the 1989 Hillsborough Disaster), it is hoped that Sir Alex will make a full recovery," the club said. "In the meantime, the club will offer its full support to Manchester United and also his family."
Read Madrid superstar Cristiano Ronaldo sent his thoughts and prayers and tweeted a photo of him with Ferguson during their Manchester United days.
He, too, wrote, "Be strong, Boss!"
Former Manchester United and Denmark goalkeeper Peter Schmeichel tweeted: "Please. Be strong. Win this one."
Schmeichel, who played for Ferguson for eight seasons, told CNN when the legendary manager left Old Trafford for retirement that Ferguson was tops in many fields.
"He is the best manager in the world and he's the best guy as well. He's a really good friend as well," Schmeichel said in 2013.
Ferguson's talent has been in managing players individually rather than as a group, Schmeichel said.
"The end result is that everyone plays really well for the team," Schmeichel said. "Yes, he can be hard, he can be tough. ... In a way, he becomes your second dad. He has to educate you in life, he has to prepare you for what comes next in life after football."
Ferguson, 76, is the most successful manager in the history of English Premier League, winning it on 13 occasions between 1993 and 2013.
Ferguson took charge of United in 1986, winning more than 30 trophies before retiring five years ago.
Ferguson, who was born in Glasgow, Scotland, began his career on the soccer pitch, playing for Scottish clubs Queen's Park, St. Johnstone, Dunfermline Athletic, Rangers, Falkirk and Ayr United.
But it was when he returned to the game as a manager, working at East Stirlingshire, St. Mirren and then Aberdeen, that people really began to take notice.
He led Aberdeen to three Scottish titles, four Scottish cups, one League Cup and one European Cup Winners' Cup before moving to United in November 1986 following the dismissal of former manager Ron Atkinson.
After a difficult start, Ferguson transformed United's fortunes.
Ferguson's teams dominated the Premier League and were crowned champions of Europe on two occasions, in 1999 and 2008.
He also led United to five FA Cup triumphs.
He was voted Manager of the Season 11 times as his teams won 528 times in 810 matches.