Jurgen Klopp admits Liverpool should have signed defensive cover last winter after injuries suffered to key players derailed their title challenge.The Reds were progressing well in the defence of their Premier League crown. They sat top of the table on December 30 following a goalless draw with Newcastle United. But the wheels fell off in the new year, with eight defeats in 12 top-flight matches.The Merseysiders rallied to qualify for the Champions League by winning eight of their last 10 games. Injuries to key defends Virgil van Dijk, Joel Matip and Joe Gomez were behind the poor run of form.Turkey international Ozan Kabak came in on loan from Schalke while Ben Davieswas bought from Preston North End. The latter has yet to make an appearance and will play for Sheffield United on loan this season.Kabak did enjoy nine league outings but neither were the big-name signing fans expected. Sky Sports pundit and former Liverpool star Jamie Carragher urged Klopp to sign a new defender after Van Dijks injury.Where next for Robert Lewandowski – Man City, Liverpool, Real Madrid or staying at Bayern Munich?He said at the time: Dejan Lovren went and they didn’t replace him so they only have three centre-backs and one of those, Joel Matip, is always injured.There are question marks now about Joe Gomez. So there is no doubt that Liverpool had to go big in the transfer market.Klopp responded by saying there are a few reasons why they [pundits] don’t do this job.Liverpool made it two wins from two games with a 2-0 victory over Burnley on Saturday. They sit top of the table and are level on six points with Brighton after goals by Diogo Jota and Sadio Mane.The Anfield outfit signed centre-half Ibrahima Konate from RB Leipzig earlier this summer. However, Van Dijk and Matip were Klopps preferred centre-back pairing against the Clarets.And the duo also started alongside each other in the opening 3-0 victory over Norwich City. Klopp now has options with his injured stars back plus Konate and the emergence of Rhys Williams and Nat Phillips.The German said he was not surprised by the performances of Van Dijk and Matip. But he hinted that the critics were right to point the finger back in January.I can tell you now already, because of what happened last year and we desperately needed the fourth centre-half, now we have six, with Rhys and Nat Phillips, we needed that, he added, per The Mirror.READ MORE: Liverpool win has pundit raving about star man who gives them title hopes