Ferguson was rescued by a legendary Mark Robins strike at Nottingham Forest in the FA Cup, which would send United on their journey to a Wembley triumph.
Knighton recalled to the Mirror: “If we had not won at Forest then Alex would have been sacked – I am 100 percent certain of that.
“Martin Edwards [United's former chairman] and Sir Bobby Charlton have tried to rewrite history by claiming that wasn't the case.
“But when we played QPR at Old Trafford on New Year's Day, I was stood in the boardroom at half-time when Martin sidled up behind me and whispered, 'we've got to be talking about the manager'.
“I almost choked on the sandwich I was eating. He made it clear he felt Alex's time was up. But then we won at Forest... the rest is history."