Even at this relatively early stage of the season, Manchester City's trip to Liverpool feels like it could be a defining clash.
Led by Jurgen Klopp and Pep Guardiola, the Premier League's top two are undoubtedly going to offer up a thriller with plenty of tactical intrigue in the way they will play.
Sportsmail has put together a tactical preview of the issues surrounding both sides ahead of Sunday's match.
Jurgen Klopp (left) and Pep Guardiola (right) will be testing their wits this weekend
Few would have predicted this after Fabinho's start to life in England but on current form the Brazilian is probably the best defensive midfielder in the Premier League.
He's so important to Liverpool that he was left out of the game against Aston Villa in order to ensure he would not pick up another yellow card and end up suspended for this match.
His compatriot Fernandinho probably merited that accolade before Fabinho really got going and yet he is unlikely to feature in his preferred role on Sunday due to City's defensive injuries.
Rodri is also not likely to be available for the champions at Anfield.
Fabinho has become one of the best defensive midfielders in England since his arrival
The way he wins the ball back and can drive up the field is crucial to Liverpool's play
That means Ilkay Gundogan will play in the No 6 position when City visit Liverpool and that could be an issue.
He is not a natural sitter, and while he has been deployed there in the past, it tends to be an issue against the best sides.
Gundogan is more useful going forward, and while that is useful when City face the usual also-rans in the Premier League, it is a problem against Liverpool.
If you compare Fabinho and Gundogan statistically then the issue becomes very clear.
When Virgil van Dijk was out of position after losing a header, Fabinho was quick to cover
He won the ball back and ensured that the opposition did not go any further up the pitch
Gundogan only manages 1.2 tackles per 90 minutes played compared to Fabinho's 2.9, highlighting the fact he is less valuable when it comes to breaking up play.
All of this could be a problem for City if Liverpool come out flying.
That's especially the case with Alex Oxlade-Chamberlain in fine form in the middle of the park and having previously shown his capacity to hit a goal or two against City.
He will also be less useful in forcing transitions, which is a crucial aspect in how both teams play, and his lack of suitability for the role means he is more likely to get caught out against Liverpool's pressing machine.
Ilkay Gundogan was under absolutely no pressure when he had the ball against Atalanta
But when two players decided to press either side of him, he turned and was caught on the ball
The counter attack that Atalanta pulled off from that position led to Claudio Bravo's red
And he can get caught out there too. Against Atalanta, pressing him with a few men saw him lose the ball, leading to a swift counter that resulted in Claudio Bravo being sent off.
It will not surprise you to hear that Liverpool have both the style and players to exploit that.
Gundogan could be a defining factor on Sunday — whether he wants to be or not.Defensive instability on both sides
As mentioned above Fernandinho is likely to play in defence for City on Merseyside and that is because Pep Guardiola has had problems at the back all season.
Aymeric Laporte has been out for most of the season after his subtle but important role in their title-winning season last time out.
Guardiola clearly does not trust either John Stones or Nicolas Otamendi particularly and tends to rotate between the pair, with Fernandinho taking up the other slot in central defence.
Given he often deployed Laporte as an auxiliary left-back in these games, over fears about Liverpool, it is a real blow to have so few defensive options available.
His problems in defence, an area Guardiola is never given enough credit for working on, has been reflected in City's recent performances.
Where in August, September and