The Reds made a disappointing start to their Champions League group stage game following a 2-2 draw with Sevilla at Anfield on Wednesday night.
Liverpool fell behind in the fifth minute after Emre Can, Alberto Moreno and Dejan Lovren all failed to clear the ball before Wissam Ben Yedder finished from close range.
The Merseyside outfit responded through Roberto Firmino after good work from Jordan Henderson and Moreno in the lead up to the goal.
Summer signing Mohamed Salah made it 2-1 with a deflected strike then Firmino missed a penalty moments before the half-time break.
Liverpool were on top for most of the Champions League clash but Argentine midfielder Joaquin Correa equalised in the 72nd minute at Anfield.
The Reds have now scored eight times in three European games in the 2017-18 season so far, while the Reds have netted eight goals in the Premier League in four fixtures.
Former Chelsea midfielder Lampard admitted that going forward Liverpool look unstoppable but cited their defensive issues as a big problem for Klopp.
“We saw both sides of Liverpool,” Lampard told BT Sport.
“Lots of good stuff. They were entertaining to watch. When they’re in that form and it clicks, they can beat any team in the world.
“If they’re going to make basic mistakes, they can lose games even ones when they’re in a fantastic position to win.”
Liverpool will host Burnley in their next Premier League game at Anfield on Saturday afternoon.
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