Sir Alex Ferguson has already addressed Gary Lineker’s claim that Manchester United’s struggles can be traced back to his departure, with the legendary manager branding it “an insult”.

Defending champions United crashed out of the FA Cup on Sunday in a penalty shootout defeat to Fulham following a 1-1 draw at Old Trafford. The Red Devils have endured a nightmare season, with the club languishing in 14th place and set for their worst ever Premier League finish.

While head coach Ruben Amorim has struggled on the pitch, co-owner Sir Jim Ratcliffe has added to the chaos off it, sparking controversy due to the swathes of redundancies and cost-cutting measures he has implemented.

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After Sunday’s latest disappointment, Match of the Day presenter Lineker discussed United’s fall from grace since the Ferguson era. He turned his attention to the Scot and the set-up he left behind after his retirement in 2013.

Lineker said: "If you look at Liverpool now, they’ve got a new manager in Arne Slot, and it’s testament to how Jurgen Klopp left the club in a really good state. So the structure is really good. That probably wasn’t the case at the end of Sir Alex Ferguson’s [time at Old Trafford]."

Ferguson won the league a record 13 times with United, including a comfortable triumph in 2012/13 despite his ageing squad. Lineker added: "I know they won the league that season. But it wasn’t their best side, and a lot of their great players were coming to the end of their careers. I think from there they had problems. The academy wasn’t delivering the players that they were before."

Such a line of reasoning regarding United’s gradual decline over the past 12 years, which has seen all seven of Ferguson’s successors struggle to varying degrees, is not new. Even as far back as 2014, once David Moyes, handpicked by Sir Alex as his successor, was sacked, there was a widespread suggestion that Ferguson had not provided enough future planning.

But the 83-year-old, who enjoyed 26 years of unparalleled success, hit back at critics and instead blamed Moyes’ failure on another factor. "It is an insult to say that I left an ageing squad," Ferguson said at an event to publicise his updated autobiography.

"Chelsea have seven players over 30 but nobody talks about them being an old team. It is easy to defend myself against all of that because all the statistics are there.

"My advice to David [Moyes] was that he should maybe keep Mike Phelan. He was a United man - loyal, hard-working and a good judge of the players. I was always supportive of David - whenever he called I gave him the advice I would have wanted when I was manager.”