Liverpool had been going well in the Champions League, with three wins from four matches.
This defeat leaves them a point off the top eight, but with tough matches against Inter Milan and away to Marseille to come.
AdvertisementAdvertisementAdvertisementFirst up, though, is a trip to West Ham in the Premier League on Sunday.
Ex-Liverpool defender Stephen Warnock said: "Every single Liverpool player at the moment needs to go back to basics, because every single player is having a tough time at the moment and needs to improve.
"Morale needs lifting but it is very difficult to lift it. There are no easy games for them."
While Liverpool's results were impressive at the start, problems were evident with new signings struggling to settle and players who stood out last season failing to offer the same quality and contribution.
The impact of Portugal forward Diogo Jota's death in July cannot be ignored.
AdvertisementAdvertisementAdvertisement"I think there's a bigger picture with everything that has gone on around the club," added Warnock.
"There's a massive difference from last year in what is going on. However, it is a results-driven industry and at the moment Liverpool are losing games very heavily and the signs aren't that they are changing - there aren't improvements.
"But, what do you put that down to? Is it down to the manager? Is it down to what has happened with Jota? I think this is a very difficult situation for the club to try to look at, because of everything that surrounds it."
Those who support the club are of course desperate for a solution, but questions remain around what it will be - and how quickly it can be found before it becomes a season to forget.
Read the analysis in full here