The Reds have a fierce rivalry with United, one many fans see as bigger than their respective derbies against Everton and Manchester City.
As such, fans of the Anfield outfit will be scratching their heads at comments made by Klopp, who feels the Red Devils squad is filled with quality.
The German believes that Jose Mourinho's side will go on to lift the Europa League trophy in May as they are "outright favourites" in the competition - the only one they have never won.
United welcome Anderlecht to Old Trafford on Thursday for the second leg of their quarter-final clash, which is delicately poised at 1-1.
"Manchester United have a tremendously well-assembled squad. They are very likely to reach the Europa League final," Klopp told Sports 1 magazine.
"They have already got injury problems. But with their extensive squad, they have been able to react to pretty much everything that has come their way.
"Recently they have had four or five men out injured and Henrikh Mkhitaryan still hasn't been able to break into their starting line-up.
'You can tell from that just how much quality they possess from the outset. United have a mix of experience, pace and quality.
"They are truly a good team. And to my mind they are the outright favourites to win the Europa League."