Liverpool's Juergen Klopp described former Manchester United manager Alex Ferguson as the "John Lennon of football" ahead of Sunday's Premier League meeting between the arch-rivals.
Klopp's comments on the man who retired having fulfilled his long-standing ambition of knocking Liverpool "off their perch" will raise eyebrows on Merseyside, especially after he compared the Scotsman to the city's most famous son.
Ferguson led United to a record 20th Premier League title before calling time on his career, eclipsing the 18 won by Liverpool, a club with whom the United manager always had a stormy relationship.
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"Maybe Sir Alex Ferguson is the greatest ever," Klopp told reporters on Friday.
"I had really good moments with Sir Alex. It was an honour to talk with him," Klopp added.
Ferguson, a master at playing mind games with rival managers, has gone on record to express his admiration for the German, who was less effusive in his praise for United's current manager Louis van Gaal.
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"I don't know Louis too well but we have had a few intensive games. We both want to be successful," the German said.
"We are different characters. He is more experienced. Maybe I'm more lively on the touchline than him, but sometimes that is not always good."
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Defender Mamadou Sakho, captain Jordan Henderson and winger Jordon Ibe came through Liverpool's 3-3 draw with Arsenal on Wednesday unscathed after recent injuries and are available to face United.
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