Barring another of the remarkable comebacks that have decorated Jürgen Klopp’s Liverpool reign, his final European game at Anfield will have featured a flat performance and atmosphere, resignation to defeat and a divide between fans and club; everything, that is, that goes against the culture he has created over the past nine years. Rediscovering the spark and belief required to win a Premier League title, however, is the Liverpool manager’s more pressing concern.

Liverpool hit a wall against Atalanta on Thursday that was not entirely of the Italian club’s making. That is to take nothing away from an exemplary display by Gian Piero Gasperini’s side, who demonstrated throughout a comfortable 3-0 victory why they are unbeaten in 11 Europa League away fixtures. Atalanta, sixth in Serie A, were clinical, tactically astute and commanding in defence against what was ultimately a four-man Liverpool attack. Their defensive organisation will be a formidable obstacle to Liverpool’s hopes of recovery next week in Bergamo, where Klopp’s team won 5-0 in a Champions League group game during the dark days of Covid in November 2020. Rhys Williams and Joe Gomez were Liverpool’s central defenders that night. But that was then.

Liverpool also hit a wall on Thursday when searching for the intensity demanded of a European quarter-final. The worry for Klopp with seven games remaining of a delicately poised title race is that fatigue has crept into several performances of late, and against Atalanta it affected players with varying conditions and workloads. Curtis Jones and Kostas Tsimikas started because they need game time after recent, lengthy injury layoffs. Both were off the pace and hooked at half-time along with Harvey Elliott.

Related: Jürgen Klopp angry that Liverpool ‘lost the plot’ in Europa defeat by Atalanta

“We didn’t take off the three worst players,” said Klopp, explaining that a lack of rhythm prompted the triple substitution. With the exception of Andy Robertson, also rebuilding match sharpness after several months on the sidelines, Liverpool’s substitutes – usually so effective in turning matches this season – also laboured. Mohamed Salah threatened several times and had a goal disallowed for offside but was comfortably contained in possession by Matteo Ruggeri and Atalanta’s captain, Marten de Roon. The tiredness of mind, as well as legs, that Klopp blamed for Liverpool’s poor decision-making in extra time of their FA Cup defeat at Manchester United was again in evidence when Dominik Szoboszlai’s loose pass led to Atalanta’s third goal. Wataru Endo, Alexis Mac Allister, Gomez and Caoimhín Kelleher, influential figures this season for Liverpool, showed understandable signs of fatigue.

It is harsh, and hypocritical, to blame Klopp’s decision to rest key players for Liverpool losing a 33-game unbeaten home run. His skilful juggling of resources amid considerable injury constraints is precisely why Liverpool have been able to challenge on numerous fronts this season. Klopp has used 30 players in the Europa League, the highest number in this season’s competition, and 35 across all competitions. Workloads are measured to the minute to ensure Liverpool finish campaigns strongly. But they are starting to flag at the worst possible moment.

“My job is not the easiest in the world, not the most difficult as well,” said Klopp after the defeat. “But it’s about when you have players you need to make sure you get them together on the pitch and then it works out somehow. With different lineups we have played really good football this year, today we didn’t. That’s the reason we lost. There can be the headline: ‘Blah, blah, blah – it didn’t work out.’ It’s absolutely fine and right. But we need them all, and we need them all aggressive, fit, going for it, a bit angry, full of desire and not so much dealing with your own situation, like: ‘I have no rhythm, I haven’t played for ages.’ You have to try to avoid that.

“Diogo [Jota] was absolutely fine, 20-25 minutes helped him a lot and we will see what we can do from there. You saw Curtis, who for the majority of the season was the fittest player and pressed like crazy over 90 minutes, he was after 20 minutes 100% surprised. I was surprised as well: ‘Oh look, he feels the intensity already.’ That is why we made the change at half-time. We don’t have to force it through. We as a group have massive quality but we didn’t show it and that is why we lost.”

Crystal Palace must be braced for a reaction on Sunday, providing Liverpool find the energy. The Kop will be decorated again with flags, which were absent against Atalanta as fans protested against a 2% increase in ticket prices at Anfield next season. Klopp, who has won more Premier League games against Palace (13) than against any other team, craves a return to normality from Liverpool as much as Dublin publicans long for the club’s continued presence in the Europa League.

“The good thing about really bad performances is that it is easy to play better, so we should start from there,” Klopp said. “This must feel bad and it does. Let the boys take it home. Nobody will sleep great and then we come together and the boys will start to recover and we go from there. We have to show a reaction definitely, 100%, that is clear, but I cannot plan the reaction 20 minutes after the game. Even I have to think from time to time and I will think about that. It is not the first time in my life that I lost a football game unfortunately and, yes, we will show a reaction, I can promise.”