The 31-year-old is irreplaceable at the heart of Jurgen Klopp's side, but therein lies one of the Reds' biggest issues.

Jurgen Klopp could not conceal his smile as the question arrived. How, he was asked, would Liverpool cope having not had a weekend fixture to help prepare them for their Champions League clash with Ajax at Anfield. 

Could it be a double-edged sword, his Dutch inquisitor wondered? Would the Reds benefit from the extra time spent on the training field, or would they potentially suffer from a loss of “rhythm”? 

Klopp’s reply was as emphatic as it was amusing.

“Which rhythm?!” he grinned. “We had no rhythm. Did you watch our game?! Losing this rhythm would be really cool!”

Defeat to Napoli in their opening Group A match means Liverpool arrive into Tuesday’s game with Ajax under pressure, both in terms of the table and in terms of the questions being asked of Klopp and his side. 

Their 4-1 loss in Italy was their heaviest in European competition since December 1966. Ajax, ironically, were the side who inflicted that one, Johan Cruyff inspiring a famous 5-1 triumph in the Amsterdam fog. 

For Klopp, Naples represented another low point. He says it was the worst performance of his time as Reds boss - “a real horror show,” - and one which made for a long and uncomfortable team meeting, as well as a few individual chats, at the AXA Training Centre last week.

Things clearly need to change at Anfield, and fast. Seven games into the new season, Liverpool have won only two and have looked convincing in only one, that bizarre 9-0 triumph against a timid, compliant Bournemouth side last month. If a positive response is expected against Ajax, the fact the visitors thrashed Rangers 4-0 in their opening group match, and are top of the Eredivisie with six wins from six, should sound a note of caution for Reds fans, and for Klopp.

He will, at least, be able to welcome back one of his most important players for Tuesday’s game, with Thiago Alcantara fit and expected to start after a second-half cameo appearance in Naples. 

The Spaniard had been absent since limping out of the Premier League opener at Fulham in August with a hamstring injury, and his return to action could hardly be better timed, given Liverpool’s midfield struggles without him. When we talk of rhythm, few are better at bringing it than Thiago.

That much was evident even in Napoli, when he left the field having won more tackles than James Milner, Fabinho, Harvey Elliott, Trent Alexander-Arnold and Andy Robertson combined, and when Liverpool had looked an altogether more cohesive side - albeit against a team that had effectively declared with the victory secure - during his half-hour on the field.

Without him Liverpool have, bar Bournemouth and a few isolated spells in other games, lost all semblance of midfield control. Fabinho has struggled, Milner has struggled, Jordan Henderson struggled prior to his own hamstring injury, and while Harvey Elliott’s promise is clear and his performances generally encouraging, the youngster cannot and should not be asked to do what Thiago does. At 19, Elliott has miles left to travel.

With Thiago on the pitch, Klopp will expect Liverpool to improve almost immediately, both in terms of their use of the ball and their ability to control the centre of the field. The former Bayern Munich man may be a purist’s dream with his disguised passes and unfathomable changes of direction, but his reading of the game, the way he picks up second balls and his ability to close down space and keep his team on the front foot will be just as valuable as Klopp plots the Reds’ recovery.

It goes without saying, but keeping him fit and healthy will be crucial. Klopp knows that Liverpool are not the same team without him - witness the lengths the Reds went to make sure he started the Champions League final in May, despite an achilles issue - and that his presence should, can and will lift the form of others around him. As Pep Lijnders, Klopp’s assistant, told GOAL back in August: “When Thiago plays, we play.”

Perhaps that shines a light on some of Liverpool’s other issues, and in particular their reluctance to sign a midfielder in the summer. Six weeks into the campaign, that looks like a gamble that could cost them.

You’ll be familiar with the story by now. Liverpool were interested in Aurelien Tchouameni, who joined Real Madrid instead. They asked about Jude Bellingham and were told no chance for this summer. Later in the window they moved for Konrad Laimer, only to be priced out by RB Leipzig, who expect the Austrian to move to Bayern Munich on a free transfer next year.

In the end Arthur Melo arrived on a season-long loan from Juventus, a short-term signing if ever there was one, albeit one with decent European and international pedigree at least. Style-wise, the 26-year-old has Thiago similarities too, albeit having never proven himself to anything like the same level. 

And so that is where Liverpool find themselves, relying on a 31-year-old with a chequered injury record to stay fit and lead them to glory. Without Thiago, they are simply not the same team, and with the likes of Naby Keita, Curtis Jones and Alex Oxlade-Chamberlain yet to feature at all this season, they have been unable to even begin to compensate for his absence.

The likes of Milner, and before that Henderson, have been a lightning rod for criticism in recent weeks, and their lack of form has been clear, but the issue is a wider one. Liverpool have a lot of midfielders, but too few who they can truly depend upon. 

Klopp will hope Thiago steps into that void in the coming weeks and months, even if history suggests he may be asking too much.

In the meantime, the Reds need their Spanish superstar to lift the gloom around Anfield and get his side playing again. Tuesday night would be a good place to start.