Liverpool's defeat to Fenerbahce was not only their second in a row but also exposed several problems. Jeremy Jacquet endured his first genuinely difficult match, while Andoni Iraola's experiment with Bradley Barcola at centre-forward failed to pay off.
The 21-year-old Jacquet had made such an assured start to his Anfield career that he was already being described as one of the best summer signings and a possible successor to Virgil van Dijk.
In Istanbul, the Frenchman encountered serious difficulties for the first time.
For Fenerbahce's first goal, he turned his back on Mason Greenwood's shot, drawing a frustrated reaction from Alisson. Jacquet was later also among those who did not cover themselves in glory for the hosts' winner.
His biggest problem was Romelu Lukaku. The Belgian no longer has his former pace but still uses his strength and body to excellent effect, and Jacquet struggled to cope with him for much of the match.
Jacquet was not the only one to struggle
Van Dijk did not look at his best after several early collisions, Kostas Tsimikas could have conceded a penalty for a push on Greenwood, and Joe Gomez also regularly had problems on his flank.
It was Liverpool's third successive Champions League match in which they have conceded three goals. They had previously rescued results against LASK and Villarreal, but this time that approach did not work.
Questions in attack too
Bradley Barcola became the fourth player Iraola has used at centre-forward this season.
The Frenchman, who had previously played on both wings since his £123 million move from PSG, began the match with a glaring error in a promising position and later failed to connect with a dangerous cross from Gomez.
Barcola looked most dangerous when he drifted back out wide.
Alexander Isak came on in the second half and scored almost immediately, illustrating the difference between a recognised centre-forward and a makeshift experiment.
For now, Barcola does not look like a convincing option at centre-forward.
The defeat in Istanbul was Liverpool's second in a row and brought their good autumn run to an end.
With nine matches in 29 days, fatigue is already apparent in the squad, and a trip to Crystal Palace is next.
If they drop points again, the pressure on Iraola will increase noticeably.
