Vicarage Road has been a tough place to visit for the Reds in recent seasons, but Jurgen Klopp's side will be keen to extend their unbeaten start to the league campaign here. A victory could take them to the top of the table once more.
It promises to be a big few weeks, with games against Paris Saint-Germain, Everton, Napoli and Manchester United all on the horizon. The Reds were victorious last time out, beating bottom club Fulham 2-0 at Anfield before the break, but know they are yet to hit top form despite their impressive results.
Here, Goal takes a look at everything you need to know ahead of Saturday's game....
The biggest doubt for Liverpool surrounds captain Jordan Henderson, who aggravated a hamstring injury on England duty.
The 28-year-old has had a stop-start campaign so far, but after training on Thursday, it is likely he will be in contention. Whether Klopp would prefer to give his skipper a few more days to recover, with a trip to Paris to come next week, remains to be seen.
Elsewhere, he should have a near full-strength squad to choose from, with the big decisions likely to surround his midfield and centre-backs.
Liverpool do not have any suspended players for this game.
Likely Liverpool Starting Line-Up
Assuming Henderson is not deemed fit enough to start, Klopp's big decisions are as follows; who will partner Virgil van Dijk at centre back, and how will he set up his midfield?
At Anfield of late, he has leaned towards a 4-2-3-1 system with Xherdan Shaqiri supplementing last season's vaunted front three. Whether he has the confidence to try that in a Premier League away game is another matter.
Shaqiri, though, would be expecting to start having shone for Switzerland during the last week. The former Stoke man could form part of a three-man midfield or, more likely, play from the right with Roberto Firmino dropping in as a No.10, linking midfield and attack.
That would demand a strong midfield duo. Fabinho struggled in his last away game, at Arsenal, but the Brazilian would be in contention to partner Gini Wijnaldum in the engine room, though James Milner and Naby Keita are also available, as is Adam Lallana.
As for the defence, the question will be whether Joe Gomez starts at right-back or centre-back. If it's the latter, then Trent Alexander-Arnold will play, if it's the former then Dejan Lovren gets the nod.
Watford Team News
The Hornets will be without defenders Daryl Janmaat (knee) and Sebastien Prodl (leg), as well as former Everton midfielder Tom Cleverley. Will Hughes picked up a knock in Watford's last game, at Southampton and will be assessed.
Interestingly, Venezuela attacker Adalberto Penaranda was this week granted a UK work permit and could be in contention to make his debut. The 21-year-old joined Watford in 2016 and has since been on loan with Granada, Udinese and Malaga.
TV Channel & Kick-Off Time
The fixture will not be broadcast live in the UK as it kicks off 3pm GMT. Highlights can be found on Match of the Day on BBC One, 10.30pm Saturday.
In the United States the game can be watched live on television on NBC Sports, kick-off 10am ET.
Best Opta Match Facts
Since beating them 3-0 in December 2015, Watford are winless in their last five Premier League meetings with Liverpool (D1 L4), shipping 17 goals in that time.
In all competitions, Liverpool have won nine of their last 11 meetings with Watford (D1 L1), keeping a clean sheet in seven of those victories.
None of the 22 top-flight meetings between Watford and Liverpool have ended goalless.
Watford have lost 15 of their 17 Premier League matches against sides starting that day in the top two of the table, beating Chelsea in September 1999 and Arsenal in January 2017.
Watford have won five of their last seven Premier League home games, losing the other two against Manchester United and Bournemouth.
Liverpool are looking to remain unbeaten in their opening 13 matches to a Premier League season for the first time since 2007-08.
Since a 2-2 draw with West Brom in April, Liverpool haven’t conceded more than once in any of their last 15 Premier League games, shipping just six goals in that time.
Liverpool’s Mohamed Salah has been directly involved in six goals in his two Premier League games against Watford (5 goals, 1 assist). Only Luis Suarez vs Cardiff has a better goal involvement per game ratio against an opponent in the competition (3.5, minimum two games).
Liverpool’s Roberto Firmino has been directly involved in seven goals in his last five Premier League games against Watford (4 goals, 3 assists), scoring and assisting a goal in their 3-3 draw at Vicarage Road last season.
Mohamed Salah and Roberto Firmino (38) are Liverpool’s joint-highest goalscorers in Premier League games under manager Jurgen Klopp.