Arsenal travel to Stamford Bridge knowing a loss pretty much means a concession of the title to Chelsea.
With Aaron Ramsey out for three weeks and Mohamed Elneny reaching the AFCON final, Arsenal are left with one orthodox central midfielder, meaning Alex Oxlade-Chamberlain will likely take the box-to-box role. His energy and power will be most welcome against a midfield containing Ngolo Kante.
Aside from that, Arsenal will need to contend with a 3-4-3 formation that has served Chelsea so well since October. Tottenham are the only team to show how to break them down – essentially by starving the two inside forwards, who pick up the ball fairly deep and progress from there. Spurs did this with a deep block of Erci Dier and Victor Wanyama. As Arsenal don’t have that luxury, it may mean Mesut Ozil drops a little deeper to form a three in midfield or that the full backs are less liberal with their attacks.
Offensively, a switch back to either Alexis Sanchez or Danny Welbeck up top is needed for some form of fluidity – we’re likely to let Chelsea dominate the ball and try to counter, meaning a rapid front three is required.
Ozil vs Kante:
The German has been laying on chances and scoring goals, but Kante is a special type of player who can shut anyone down.
Costa vs Mustafi/Koscielny:
The Brazilian was unable to bully the duo last time, but this is a very different Chelsea side and system.