Prompting huge concern for the 84-year-old former manager who remains a constant presence at the club he defined for more than two decades, Ferguson had arrived at the stadium on Sunday for the Premier League fixture but was transported for emergency treatment around an hour before kick-off as a precaution.
Manchester United officials indicated there was no immediate suggestion of a serious issue, with hopes he would soon be recuperating at home.
The incident comes amid continued scrutiny of the club's direction under new leadership, with co-owner Sir Jim Ratcliffe implementing sweeping changes behind the scenes.
Ferguson, who won 38 major trophies during a 26-year spell in charge of the Red Devils before retiring in 2013, has remained a regular at Old Trafford, frequently watching from the directors' box as the club navigates a turbulent modern era far removed from the dominance of his reign.
Ferguson previously spoke about his own mortality following the brain haemorrhage he suffered in 2018, recalling in his documentary Never Give In: "There were five brain haemorrhages that day. Three died, two survived. You know you are lucky."
The episode marked one of several major health challenges for Ferguson in recent years.
After undergoing emergency surgery in 2018, doctors reportedly gave him only a 20 per cent chance of survival - odds he defied in a recovery which became central to the narrative of resilience explored in Never Give In.
The film also revisited the defining moments of his managerial career, from his early battles to rebuild Manchester United to the sustained success that delivered 13 Premier League titles and two Champions League triumphs.
Away from football, Ferguson experienced profound personal loss in 2023 when his wife Cathy died aged 84 after 57 years of marriage.
Her death prompted tributes across the football world, reflecting the deep connection between Ferguson's family life and his career at Old Trafford.
Since stepping down as a manager in 2013, Ferguson has continued to serve as an ambassadorial figure for Man Utd, although the role was later scaled back as part of cost-cutting measures introduced by Ratcliffe following his investment in the club.
The move formed part of a wider restructuring effort amid financial concerns and on-pitch inconsistency.
Explaining the decision, Ratcliffe said: "I sat down with Alex, just the two of us in the room.
"I said: 'Look, the club isn't where you may think it is. It is spending more than it's earning and we're going to finish up in some difficulties. Honestly, we can't really afford to continue to pay you two million pounds($A3.8 million) a year'.
"I said, 'I'm going to leave it with you, let you have a think about it'.
"It was very grown up, maybe a little bit grumpy at the beginning, but he got it. He came back three days later, after talking to his son.
"He said: 'Fine, I'm going to step away from it. My decision'. I think it reflects really well on Alex because he put the club before himself."
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