Liverpool brought in two full-backs in the summer transfer window in the form of Javier Manquillo on loan from Atletico Madrid and Alberto Moreno from Sevilla.
But the Champions League winner highlighted Jon Flanagan's return to the side as being potentially vital for the Reds this season.
In a discussion with his former teammate on twitter, the former German international said:
@Carra23 Full back positions will be their Achilles heel this season. Not sure about any of them. Need Flanagan back.— Didi Hamann (@DietmarHamann) August 26, 2014
The Reds have several options in the full-back positions. Glen Johnson looked as if he had been earmarked as the number one right-back despite a loss of form, though a thigh injury he picked up in the 3-1 defeat to Manchester City could mean a spell on the sidelines for the defender, whilst Jose Enrique is trying to build up fitness after a knee problem blighted his season last term.
Alberto Moreno made a big error on his debut against City which led to a goal but otherwise put in a decent debut performance, whilst Javier Manquillo played in the opening day win over Southampton
It's interesting that Hamann rates Flanagan highly enough that he thinks he should be back in the starting line-up as soon as possible. The 21-year-old was impressive during his spell in the side last season and can operate on both flanks though he is unlikely to be used more on the right side this term.
However, a knee injury towards the end of pre-season seems to have kept him out of the side going into this campaign so it may be a little while before he is in a position to be considered by Brendan Rodgers.
But there does seem to be a lack of tough tackling from Liverpool's defence in the early part of the season, something which Flanagan provides plenty of.