Liverpool host Arsenal on Saturday in a lunchtime battle with potentially large implications for the Premier League title race and the battle for the top four.
In this article, I take a look at five key tactical battles that may influence the outcome.
At the Emirates in November, Cissokho, playing at wing-back, had to be withdrawn at half-time, so utterly was he dominated by Rosicky.
Although Liverpool are likely to start with a back four this time, it seems a reasonable guess that Arsene Wenger will again deploy the Czech against the left-back.
A sense of what might have been always lingers over Rosicky, who, at 23, was one of the stars of Euro 2004 before the injuries struck. But this has been a good season for him—an energy and drive underpinning his technical gifts when he has been fit enough to play.
Ozil is not quite in the form he was in the weeks immediately after his arrival on transfer deadline day, but he will still provide a serious challenge of the much-questioned defensive capabilities of Gerrard.
There are few players better than Ozil at finding space and creating a vital half-yard, and Gerrard will know that, if his discipline slips for a second, he is likely to be punished.
At the same time, Ozil isn't the best at tracking runs, so if Liverpool do begin to dominate, Gerrard may find his forward surges untended.
Both players, ultimately, are likely to offer the other opportunities.
Assuming Brendan Rodgers sticks to his 4-1-3-2, helping protect Cissokho in the left will be Henderson, arguably the revelation of this season.
He is probably still more effective in a central role and has offered hints this season that he could be the long-term successor to the player Gerrard used to be, but he can fill in diligently on either flank and, at the very least, should check the forward thrusts that have been such a feature of Sagna's play this season.
If Raheem Sterling plays on the other flank, Henderson's role is as counterbalance, and he will have to shift towards the centre at times to offer defensive cover: It's an unglamorous role, but one that is essential.
Before the league meeting of the sides earlier in the season, much of the buildup talk focused on how Arsenal would stop Liverpool's free-scoring front pairing of Luis Suarez and Daniel Sturridge.
As it turned out, they stifled them by denying them any kind of service as Liverpool looked short of creativity without Coutinho, who was only introduced at half-time.
It's possible he will play on the left, but with Arsenal's injury crisis leaving them so short of central midfielders that Alex Oxlade-Chamberlain was forced into the role against Crystal Palace last Sunday (something he actually did very well, scoring twice), the likelihood is surely that Rodgers will use him centrally again and look to exploit the lack of defensive experience alongside Mikel Arteta.
At some point, every Liverpool match becomes Suarez against one of the centre-backs. Arsenal will surely try to ensure that, as far as possible, it's Koscielny rather than Per Mertesacker who picks up Suarez, given the German's lack of pace; certainly if Mertesacker is ever isolated with Suarez running at him, Arsenal are in trouble.
The partnership between Koscielny and Mertesacker has been one of Arsenal's great strengths this season. But their strength is in one picking up a lone central striker and the other covering; against a strike, pairing the dynamic is very different and, if the cover in front of them is less secure than usual, that could be an area Liverpool can exploit.
Much, though, will depend on what happens elsewhere in midfield: Back in November, Suarez and Sturridge spent most of the game watching Arsenal boss midfield, which meant they never got anything like the service they required.