Jamie Carragher has revealed that Sir Alex Ferguson was instantly worried when Liverpool appointed Jurgen Klopp in 2015.
The German has been a revelation for the Reds leading them to a Premier League title and a Champions League crown during his time on Merseyside - something he could potentially repeat this season.
Liverpool are still fighting on all fronts at the tail end of the campaign after winning the Carabao Cup in February, securing their place in the FA Cup final and Champions League semi-final, as well as being two points clear of Manchester City in the league following their 4-0 win over Manchester United on Tuesday night.
It would be unprecedented for the Reds to win the quadruple but it's a real possibility as Klopp's men hit top form at the perfect time. It was impossible to predict that Klopp would have been such a huge success, but Ferguson seemingly had an inclination that he would do well.
The legendary Old Trafford manager approached Carragher at Michael Carrick's testimonial just after Klopp was appointed and said he was "worried" about the German being in charge of United's rivals.
Carragher said on The Gary Neville Podcast: "When you think of those managers, and I always think with the great managers, and we never had one who was acclaimed like a Ferguson, or what Jose [Mourinho] was at Chelsea, or what [Arsene] Wenger was at Arsenal, that's what Klopp is right now.
"I used to always feel [with] those managers, there was the fear but there was also the love – so the never wanted to let them down but they were absolutely terrified of them. So when you see Jurgen Klopp, he's bigger than any player. If you ask any Liverpool player who they would ant to lose – Van Dijk or Jurgen Klopp, they'd say Van Dijk, I can absolutely assure you. Jurgen Klopp is an absolute god here, but with the players as well.
"You can see and feel that energy from the side of the pitch. When Jurgen Klopp first came to Liverpool we knew he was a character, he was a personality, I actually said at the time this wasn’t a signing just for Liverpool, it was for the Premier League.
"You knew there was something special. I played in a game at Old Trafford, I think it was Michael Carrick’s testimonial, and Alex Ferguson went around the dressing room shaking hands, saying 'thanks for coming', I think he was manager of one of the teams. Jurgen Klopp had been at the club about a month and he [Ferguson] came to me and said, 'you've got a manager'. I went, 'oh yeah, good, Jurgen Klopp's made a decent start', and he [Ferguson] went, 'no, no, I'm worried'".
"And that was at the time I think Manchester United were still above Liverpool, but he [Ferguson] knew through meeting him I think at the UEFA meetings or the Champions League, wherever it was, he could feel that sort of personality. "You talk about great managers and tactics and formations, the great managers all have that, of course they do, but it's a force of personality, and that's what Klopp has, that's what Sir Alex Ferguson's got."
Fergie's intuition has proven to be spot on given what Klopp has achieved at Liverpool. And Carragher reckons there will be a colossal void to fill whenever when he does leave the club.
He added: "I think at the end of his [Klopp's] time, it will feel like when Bill Shankly left Liverpool. The feeling with Liverpool supporters already is, 'he's not going to go in two years is he?'. People are already thinking about that now because of the effect he's had on this football club."
