The Reds have completed two summer transfer deals so far but Klopp has been focused on improving his attacking options.
Liverpool spent a club-record £36.7m fee on AS Roma winger Mohamed Salah and England Under-20 international Dominic Solanke completed a free transfer from Premier League champions Chelsea earlier this summer.
Klopp relied on versatile midfielder James Milner in an unorthodox left-back role throughout most of the 2016-17 Premier League campaign.
Indeed, Spain international Alberto Moreno spent the entire season out of favour after his erratic performance in a 4-3 win at Arsenal on the opening day of last term.
Former Liverpool defender Nicol questioned Klopp’s failure to sign a left-back in the summer transfer window given his reliance on Milner last term.
“It’s bad enough this time last year he was saying James Milner is going to be left back next year,” Nicol told ESPN FC.
“I thought maybe he is a clever guy and he had somebody lined up who had another year on his deal and they’d be able to get him on the cheap. I thought he had somebody ready in 12 months time. I’m sat here still waiting for a left-back.”
Liverpool finished in fourth place in the Premier League in their first full season under Klopp.
The German head coach is preparing his team for a return to the Champions League next term.
The Merseyside outfit signed seven players in the summer transfer window last year.
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