That is according to pundit and former professional footballer Alan Brazil, who says Liverpool cannot rely on James Milner in that position.
Milner has been used on the left side of defence for the majority of the season after Spaniard Alberto Moreno had an unconvincing start to the campaign.
The 31-year-old had spent almost the entirety of his career before this term as a midfielder and Brazil's radio co-host Ray Wilkins believes that is where he should play.
"James has done well at left-back but he is a midfield player or a wide player," Wilkins said on talkSPORT.
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Jurgen Klopp has been told to bring a new left-back to Liverpool this summer
If you're going to win the Premier League, you need a better class, younger, than poor old James Milner
Alan Brazil on Liverpool star James Milner
Milner joined Liverpool on a free transfer from Manchester City in 2015 and has made 64 league appearances for the Anfield outfit.
Brazil admits he has been a good signing but with the addition of Champions League football next season, thinks they need to be looking at a higher quality replacement.
"James has been brilliant on a free, let's not kid ourselves," the former Ipswich and Manchester United forward said.
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James Milner has been used as Liverpool's left-back for most of this season
"But I'll say it again and people will hate me for saying it, if you're going to win the Premier League, you need a better class, younger, than poor old James.
"James has been great and he's been a brilliant buy.
"But I'm sorry, if you're going to take on Barcelona, Real Madrid, Bayern Munich, I'm sorry."