Duncan Ferguson was "surprised" after Roy Keane admitted he would "stay away" from the former Everton and Newcastle striker during games.
Keane will go down as one of the toughest players to grace the Premier League and beyond, but even he was intimidated by Ferguson and his no-nonsense approach.
The former Scotland international, who became the first and only professional player in Britain to be jailed for an on-field offence, when he landed a headbutt on defender John McStay, was as physical as they come.
In total, he accumulated eight red cards across his 12-year spell in England's top flight, where he holds the joint record for most dismissals alongside Patrick Vieira and Richard Dunne.
Such was his reputation, Keane has previously admitted he would actively avoid Ferguson whenever they came head-to-head.
There aren't many pictures of Keane and Ferguson in the same shot. Image credit: Getty While discussing the Scot during live coverage of Everton’s FA Cup quarter-final clash with Arsenal on ITV in 2014, he said: “I used to stay away from him. We’re talking about characters earlier and he’s certainly that."
Keane added: "He was a top, top player and he’s obviously been promoted up the last two or three weeks to work with the first team and no doubt the strikers at Everton will learn a lot from him.”
More than a decade later and Ferguson has finally responded to those comments from Keane as he gave an insight into coming up against the former Republic of Ireland international.
"They (Man Utd) had Roy Keane, who was world class," he wrote in his Autobiography, Big Dunc: The Upfront.
"He had aggression, ability, and everyone respected his ferocious work ethic. Keane was tough as anything, wasn't he? He actually said in one of his TV programmes that he 'used to stay away' from me."
Another rare picture of Keane and Ferguson together. Image credit: Getty "That surprised me," added Ferguson. "Believe you me, Roy, it would have been tough for us to square up to each other, because I had the same idea. Keane never shied from any tackle, never shied away from anything - any player, any team, any adversity. That's one of the reasons I admired him."
Duncan Ferguson became first British player to be jailed for on-field incident
As mentioned above, Ferguson became the first and only professional player in Britain to be jailed for an on-field offence when he headbutted an opponent in 1994.
More than three decades ago, the towering striker made headlines when he landed a headbutt on defender John McStay during a Scottish Premiership clash between Rangers and Raith Rovers.
Kenny Clark, the referee, had been looking the other way and didn't give a card.
But the flattened McStay was left with a cut lip and Ferguson was later convicted of assault at Glasgow Sheriff Court after losing his appeal. In total, he was sentenced to three months in jail, with the prison sentence being his third conviction for assault.
As well as being banned for 12 games by the Scottish Football Association, he served 44 days in the city's Barlinnie prison before being released.
Speaking to Everton fan channel Toffee TV in 2019, Ferguson opened up on life in prison.
"It was wrong me being there, it wasn't fair," he said. "I shouldn't have been in there and I think a lot of people understood that. It's not as if I was in for doing anything bad really. My God, it was nothing.
"The fans got me through it, a lot of them wrote to me. It was unbelievable all the letters and the support that I got."
Ferguson added: "I got all the letters when I was in there and obviously you have got a lot of time on your hands when you're in there to read through them all.
"It definitely gets you through it and you never forget those things."