There was plenty for Liverpool supporters inside Anfield to become perplexed with on Wednesday.
But there was only one incident that caused a collective hush to descend upon the stadium.
Less than 20 minutes in, Fabinho crumbled to the turf after being caught by falling Napoli forward Hirving Lozano, left nursing a sore left ankle before hobbling off and later away from the stadium in a protective boot.
The Brazilian was always going to miss Saturday's Premier League visit of Brighton and Hove Albion through suspension after picking up five bookings.
Liverpool have managed without a key player before this season, Adrian admirably deputising for Alisson Becker in the early months.
Fabinho has undergone tests on his ankle with Jurgen Klopp expected to address the player's fitness at his press conference on Friday.
But what options do the Reds have in the number six role if the talisman faces a lengthy spell on the sidelines?
Jordan Henderson
Before Fabinho arrived, Henderson was the man tasked with holding the midfield together and protecting the back four.
If not his natural game, it was one to which the skipper approached with his usual professionalism.
It was enough to help the Reds secure successive top-four finishes and win through to the Champions League final in 2017/18.
But while he still does the job regularly for England, Henderson hasn't played as a number six for Liverpool since March.
Gini Wijnaldum
The most likely option, given the Dutchman deputised impressively for Fabinho when replacing him against Napoli.
Wijnaldum earned the trust of Klopp in defensive midfield when performing impressively at Manchester City in the Champions League 18 months ago.
Indeed, with Fabinho given time to adapt and Henderson rested after his World Cup exploits, Wijnaldum started last season in the role.
His last such outing was in the 2-1 win at Southampton in August, with his game intelligence shining along with his usual athleticism and use of possession.
Adam Lallana
Lallana raised eyebrows in the summer when he revealed Klopp had a specific role in mind for him this season.
And there was even greater surprise when it emerged it would be as a number six.
Lallana filled the role in the Carabao Cup win over MK Dons and played 84 minutes there in the Premier League against Aston Villa, Klopp counting on his ability as a deep-lying playmaker.
Brighton, while more progressive this season than in recent campaigns, will no doubt be on the defensive on Saturday.
Liverpool's team selection this weekend could be hugely instructive.
James Milner
Milner hasn't played as a defensive midfielder since, coincidentally, Liverpool won 5-1 at Brighton and Hove Albion in December 2017.
The Reds fielded an unusual 3-4-2-1 formation that afternoon, so even then the veteran was in a two alongside Henderson.
Milner has stepped in from the bench into a withdrawn role in a 4-2-3-1 on a number of subsequent occasions, such as against RB Salzburg this season.
And if Klopp reverts to that formation, he could be an option.
Naby Keita
The wildcard, not least because the Guinean hasn't featured much in the last six months.
Keita's all-round game means he has the athleticism to do the job, but is lacking in terms of experience having rarely featured in the role during his career.
Even in a two, it would be a big call for Klopp to put his faith in the 24-year-old.
