The Reds have come in for criticism for their failure to string together a series of consistent results in the Premier League under Jurgen Klopp so far this season.
The Merseyside outfit were heavily linked with a move to sign Southampton defender Virgil van Dijk in the summer transfer window but a move failed to materialise for the centre-half.
Liverpool have conceded 17 goals in their first 11 Premier League games so far this season, more than any of the teams above them in the table.
And former Chelsea star Lampard believes that it is crucial for the Reds to address their defensive problems when the January transfer window comes around.
Asked who he thinks Liverpool need to sign in January, Lampard told BT Sport: “[They need] centre-halves. They have to address that.
“And they need a goalkeeper. There’s still a question mark about who is their goalkeeper, rather than saying who is the main man – and that brings inconsistency.”
Liverpool return to Premier League action after the international break with a home clash against Southampton at Anfield on Saturday 18 November.
The Reds have won five, drawn four and lost two of their opening 11 games in the Premier League so far this season as they look to try and claw their way back into the title race, with the hectic festive period now looming large.
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