Hammers hoping to make a statement
It's the acid test for in-form West Ham as they look to prove they're the real deal by beating Liverpool and actually moving above the Reds in the Premier League table.
The Hammers are fourth and just two points behind Jurgen Klopp's side yet go into this huge home game as huge underdogs as they've still not convinced the bookies that they're genuine Champions League contenders.
Just two defeats out 16 games in all competitions this season (W11 D3) says they must be respected, but losing their one and only league game against a side in the top eight of the table after 10 games (Man Utd at home) says they still need that statement victory.
And that's because West Ham under David Moyes have been pretty good against the rest of the league but have just not been able to get it done against the big boys. Consistency has been key with Moyes making the fewest changes to his starting XI, just four this season in the league.
After ending Man City's Carabao Cup reign though, albeit on penalties, this could be a landmark game for them against one of the three title contenders this season. A win here, and suddenly it'll be time to take West Ham seriously.
Unbeaten Reds in rampant away form
Klopp will be under no illusion about how tough this trip to the London Stadium should be, even if Liverpool have won four of their last five trips to West Ham and have won eight of the last 10 overall.
The Reds are also on a joint club-record 25-game unbeaten run after Wednesday's win over Atletico Madrid, which also booked their place in the Champions League knockouts with two games to spare. In the Premier League it's 20 games without defeat with at least one goal scored in each one.
Letting a two-goal lead against Brighton was a blow, and some are concerned that Klopp's side are already looking like drawing too many games - but it's not been a major problem away from home with four wins out of five and a staggering amount of goals scored.
Liverpool have scored three or more in their last six Premier League away games - only the 1892/93 Birmingham City side have managed to do that in seven straight away games in the history of the Football League. In all competitions only Preston have stopped Liverpool scoring three times in the last 10 away games.
Roberto Firmino looks set to miss out after picking up a hamstring injury and that could be a key injury even though Diogo Jota is a more than capable stand-in in that front three. Jota looked sharp against Atletico and is an underrated goalscorer - bagging three in four away league starts this season.
Midfield has been Klopp's big area of concern but Fabinho started on Wednesday and Thiago Alcantara came off the bench - if both can play on Sunday that'll be a massive boost.
Reds huge favourites
For a side fourth in the table, just two points behind their opposition and playing at home, West Ham are a massive price at 4.67/2 to win this one. They've won 62 points in 2021 which already their best ever return in a calendar year and third behind only Man City and Chelsea.
Liverpool are as short as 1.705/7 for a sixth straight away win in all competitions, but both Brentford and Brighton have shown that you can get at Klopp's side if you gamble and send men forward, playing at pace. Seeing Moyes going for it with the same reckless abandon seems a little far fetched though.
Given Liverpool have had four draws already, the 3.9 on another stalemate here will prove popular in some circles with West Ham looking the sort of capable and organised side who could offer up a severe test.
Stopping top scorers Liverpool from finding the net would appear to be Moyes' best shot, but that's easier said than done with only Chelsea keeping Liverpool from scoring more than once in the last 21 games.
Real Madrid were the last team to keep a clean sheet against Liverpool back in April, with Fulham the last team to keep them out in the league 20 games ago. Liverpool are 2.757/4 to score three away goals yet again.
Streaking Salah eyeing more records
Mohamed Salah is already ahead of the scoring schedule from his insane debut season at Anfield, and with a goal in Liverpool's first five away games he's matched Thierry Henry and is a goal here away from setting a new record.
It's no surprise to see Salah as short as 1.758/11 to score again - especially given his stunning record of nine goals in eight games against West Ham, he's almost automatic against the Hammers.
Michail Antonio is the main man for West Ham and he loves being involved at the London Stadium, with 11 goals and six assists in his last 22 league games at home - on a ground where he has scored the most goals (19) and made the most assists (12).
It'd be no surprise if he found the net at 2.89/5 and he's the West Ham man you want to be on, even if the club have had nine different scorers this season - again only City and Chelsea have more - so threats can come from multiple angles.
You can usually bank on a fast start for Liverpool, as they've been ahead at half time in seven of their 10 Premier League games and haven't yet trailed at the break - in fact they've only gone in at half time behind once in 16 competetive games this season.
Liverpool to lead after 45 minutes on Sunday is 2.26/5, with 2.56/4 on them winning in the HT/FT market. Those betting in-play should note that nine of Liverpool's 10 Premier League games have seen the same full-time result as at half-time.