After winning two trophies and finishing runners-up in the Premier League and Champions League last season as they pushed for an unprecedented quadruple, few could have foreseen the way the Reds have dropped off.
Liverpool had also impressed in July's Community Shield win over Manchester City, but the curtain raiser proved a false dawn given they have only won two of their opening six Premier League matches.
That challenging start was compounded by an embarrassing 4-1 defeat at Napoli in Wednesday's Champions League group opener, leading Klopp to talk about the need to "reinvent" and Robertson to call for introspection.
"We need to put our finger on it," the left-back said after a night when Piotr Zielinski's brace was complemented by goals from Andre-Frank Zambo Anguissa and Giovanni Simeone before Luis Diaz pulled one back.
"We have to work out why that's happening.
"I can't put my finger on it just now because if we did it would have been sorted. But we have to get back to it.
"Our intensity over the years has been incredible, the way we work together, the way we press teams, the way we put them under pressure. And just now that's not happening, that's evident. It's not happening.
"The fans aren't daft, they can see it on the pitch as well. We need to do it quickly.
"We need to get our relationships stronger, we need to keep working on the left-hand side, the right-hand side, the midfield, the strikers have to be closer to all of us, we have to get back to being compact.
"We also need to get back to keeping clean sheets - we've not kept enough this season and we need to get back to it because that's the basis of a good game.
"When you keep clean sheets you know you can't get beat, it's as simple as that. We've conceded four (against Napoli), probably deserved it. They could have probably had more, Ali (Alisson) has saved a penalty.
"We could have scored a couple of goals but we're not interested in that. We deserved to get beat and we need to be so much better."