The Reds could still finish in any position from first to bottom of Group C but know that only a win will do against Napoli if they are to stand any chance of reaching the last 16.
The term 'must-win game' is often inaccurately used in football, but for Liverpool anything other than victory on Tuesday night will see them eliminated from the Champions League just seven months after reaching the final of the competition.
Group C was tipped to be one of the most fiercely-contested sections of the tournament from the moment Liverpool, Napoli and Paris Saint-Germain were all drawn in the same group as each other, and so it has proved.
Liverpool go into the final match sitting third in the standings, three points adrift of Napoli and two behind PSG, and the situation is further muddied by the contrasting head-to-head records between the trio.
The Reds' situation is still in their own hands to a certain extent, but the result of PSG's match away to Red Star Belgrade will also have an impact on what Liverpool need, and there is still a scenario where Jurgen Klopp's side could beat Napoli but still crash out of the competition.
If PSG beat Red Star then Liverpool must win either 1-0 or by two clear goals to finish above Napoli, while if PSG draw in Belgrade and Liverpool win then there will be three teams locked on nine points. In that situation, Liverpool would top the group by virtue of the three-way head-to-head record, while second place would depend on the final score at Anfield.
The calculators may be required at some stage, then, but however complicated the possible permutations could be, Liverpool know that a 1-0 triumph or victory by two clear goals is what they need to guarantee their place in the knockout stages.
It is sure to be a cracking atmosphere under the lights at Anfield, where Liverpool have picked up maximum points in the Champions League this season and are unbeaten in 10 games in this competition stretching back to October 2014.
It is on the road where Liverpool's problems have come in Europe so far, losing all three of their away group games for the first time in their history to leave themselves in such a precarious position.
Anfield has been a fortress in comparison, though, and they have not lost a league or Champions League game in front of their own fans since April 2017, including nine wins from their last 10.
As if the occasion itself was not enough to crank up the volume levels on Merseyside for this match, Liverpool will also be coming into the match sitting top of the Premier League table courtesy of their 4-0 win over Bournemouth on Saturday, with Manchester City falling to defeat at the hands of Chelsea later that day.
Another mouth-watering showdown with Manchester United awaits on Sunday too, completing a huge week for Liverpool, but all of their focus will be firmly fixed on the visiting Italians for now as they look to produce another memorable European night at Anfield.
Recent Champions League form: WLWLL
Recent form (all competitions): WWLWWW
Carlo Ancelotti is the last person who will need telling how pivotal a role Liverpool fans can play in roaring their team on to a result in Europe.
The Italian was in the AC Milan dugout when the Reds came from 3-0 down to lift the Champions League for a fifth time in the 2005 final, and this time it is a three-point lead he brings up against the Premier League outfit.
However, despite sitting top of Group C with just one game remaining, Napoli still have work to do if they are to book their place in the last 16.
The visitors' permutations are more straightforward than Liverpool's; avoid defeat and they will qualify, while even a loss could be enough should PSG fail to beat Red Star Belgrade, or Liverpool fail to win by more than two goals.
A European trip to Anfield is never straightforward, though, particularly for a team that has failed to win any of their last six Champions League matches and has been beaten on their last three visits to England.
However, Napoli only need a point and that is exactly what they have managed from both of their two away games in the competition so far this season, including a 2-2 draw with PSG which saw the Ligue 1 giants score a late equaliser.
Ancelotti's side are now unbeaten in their last 12 games across all competitions stretching back to September, with the first match in that run being their 1-0 win over Liverpool at the Stadio San Paolo.
A repeat of that result at Anfield would see Napoli win four matches in a row for the first time since February, having thrashed Frosinone 4-0 on Saturday to make it three on the bounce.
Defeat, however, could once again consign them to Europa League football in the New Year, having also failed to progress from the Champions League group stages last season.
Recent Champions League form: DWDDW
Recent form (all competitions): DWDWWW
Dejan Lovren remains a doubt due to concussion and Joel Matip could therefore start alongside Virgil van Dijk once again, with Andrew Robertson set to complete the back four after making his own return at Bournemouth.
Liverpool possible starting lineup:
Alisson; Alexander-Arnold, Matip, Van Dijk, Robertson; Henderson, Wijnaldum; Shaqiri, Firmino, Mane; Salah
Napoli possible starting lineup:
Ospina; Hysaj, Albiol, Koulibaly, Rui; Callejon, Allan, Hamsik, Zielinski; Mertens, Insigne
Head To Head
Tuesday's match will be just the fourth meeting between these two clubs, with the most recent of those coming in the reverse fixture when Lorenzo Insigne scored a 90th-minute winner.
The overall record between the two is now evenly poised at one win apiece and one draw, with Liverpool having won the only previous Anfield meeting 3-1 courtesy of a Steven Gerrard hat-trick in the final 15 minutes of their 2010-11 Europa League contest.
The two sides had played out a goalless draw in Naples prior to that.
We say: Liverpool 2-0 Napoli
It is occasions like these which have earned Anfield the reputation of being one of the great European stadiums, and it is sure to be rocking for this match. The game is balanced on a knife edge, but we're backing Liverpool to get the win they need to progress.