Much has been made about Hoffenheim’s talented manager Julian Nagelsmann but he was put in his place by Jurgen Klopp night.Liverpool secured a 4-2 win victory over the German club at Anfield, completing a 6-2 victory on aggregate, to book their place in the Champions League group stage.The Reds were simply flawless. They were completely unstoppable at times going forward, with Sadio Mane, Roberto Firmino and Mohamed Salah helping their claim to be known as the best attack in the Premier League and among the finest in Europe.Salah and Firmino were both on the scoresheet and Mane was just devastating, playing a part in both of Emre Can’s goals.So good was Mane that Steven Gerrard sung the Senegalese’s song on live TV at half-time.So, a terrific night for Liverpool and Jurgen Klopp. Champions League football is back at Anfield and for a club that has won the competition five times, that feels right.But while Liverpool’s attack was outstanding, their defensive vulnerabilities were noticeable once again.So much so that former Red John Arne Riise singled out one player for criticism.

John Arne Riise ruined Dejan Lovren

Dejan Lovren was at fault for both Hoffenheim goals, giving the ball away carelessly for the first and being beaten in the air for the second.

And Riise believes Klopp has to bring in competition to challenge Lovren for a starting spot.

Riise wrote: “[Hoffenheim’s Havard] Nordtveit isn't good enough at this level, Not sure Lovren is either!

“Surely we have or there is better CB then Lovren? He makes too many mistakes. He said he wanted to show he is one of the best in PL??

“I think Lovren need more competition or more pressure to get to his best. Look at Moreno, Stepped up and proves he got it.”

Watch: Lovren at fault for Hoffenheim's first goal

Van Dijk move

Liverpool seem to have given up on signing Virgil van Dijk from Southampton but, with just one week remaining of the transfer window and Lovren being noticeably poor, it wouldn’t be a surprise to see the Reds renew their interest in the wantaway centre-back.

If it’s Van Dijk’s hefty price tag that is proving the problem, there’s an easy solution: Sell Philippe Coutinho for £150 million to Barcelona.

On this display, Liverpool can get by without the Brazilian.

Should Liverpool sign a centre-back? Let us know in the comments section below!