The Reds secured a commanding 2-0 aggregrate lead in the first leg of their Europa League last-16 clash thanks to goals from Daniel Sturridge and Roberto Firmino.
The England striker broke the deadlock from the penalty spot before Firmino finished from close range in the 73rd minute.
Philippe Coutinho and Adam Lallana wasted opportunities to extend the home side’s lead ahead of the return leg at Old Trafford next Thursday.
Former Liverpool midfielder McManaman heaped praise on Klopp’s side after an outstanding performance at Anfield.
“They were excellent. The only thing you can say about Liverpool is that they didn’t score more to really wrap up the tie,” McManaman told BT Sport.
“If Manchester United put this type of team out, Liverpool will go and score goals there next week. It is the most disjointed Manchester United team I’ve ever seen.”
United had won their last four meetings against bitter rivals Liverpool ahead of Thursday night’s clash.
The Red Devils will face West Ham United in their FA Cup quarter-final at Old Trafford on Sunday ahead of the visit of Liverpool next Thursday night.
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