Former Liverpool defender Jamie Carragher has identified the Reds' shortcomings on the pitch during their humiliating 4-1 loss at Napoli in the UEFA Champions League Group A opener on Wednesday (September 7).Liverpool opened their continental campaign on a disastrous note as Luciano Spalletti's side steamrolled their way to victory at the Diego Armando Maradona Stadium. Piotr Zielinski scored twice while Franck Zambo Anguissa and Giovanni Simeone scored once each. Luis Diaz pulled one back in the second half for the hapless visitors.The Athletic UK@TheAthleticUKThe gulf between Napoli and Liverpool's xG... 🤯#NAPLIV | #LFC | #UCL41432The gulf between Napoli and Liverpool's xG... 🤯#NAPLIV | #LFC | #UCL https://t.co/xo11P1B67fSpeaking to CBS Sports, Carragher claimed that the Reds' lack of intensity in the center of the park is the main reason, not their defensive high line, behind their poor start to the season. He elaborated:"We mentioned that before the game, this is a problem – the high line and that they aren't actually getting pressure on the ball. The thing for me, right now is that Liverpool play a high-risk game, but they're not pressing the ball to stop that high-risk game and it’s causing them the problem."He continued:"It's not a problem with how high the line is, it's about being compact, being together. But when someone gets time on the ball. So often we say, it's too easy to get through Liverpool’s midfield. That didn't happen before, so you could play that high line and be really compact. But if that's not happening, you have to adapt."He added:"It's embarrassing, it really is. I said before, it's kids' stuff and this is the big problem right now. They've built their success on intensity on the ball, which means their opposition can't get their head up to put the ball over. So your team is always tight and always really compact, always a risk, but you’ve got energy on the ball. That energy is not there now."Liverpool will next lock horns with Wolverhampton Wanderers at Anfield in a Premier League contest on Saturday (September 10).Anfield Watch@AnfieldWatch Jurgen Klopp on needing to reinvent the team:“We definitely have to kind of reinvent ourselves because just basic things were not there.” 26518📺 Jurgen Klopp on needing to reinvent the team:“We definitely have to kind of reinvent ourselves because just basic things were not there.” 🔴 https://t.co/nCNPmFXv5OLiverpool in risk of falling behind in Premier League race due to poor formEver since their 3-1 victory over Manchester City in the Community Shield on July 30, the Reds have looked like a shadow of their former selves. The club are currently seventh in the Premier League standings with nine points from six matches.Jurgen Klopp's side have registered just two Premier League wins – against Bournemouth and Newcastle United – so far this season. After taking on Wolverhampton Wanderers in the upcoming weekend, the club are scheduled to face Chelsea, Brighton & Hove Albion, Arsenal, Manchester City and West Ham United in their next five matches.