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The men who will miss this match may be almost as important as the ones who play it.
For various different reasons, five of the players who started the game at the Emirates on December 23 are sidelined.
Willian and Ramires, both dismissed at Villa Park last weekend, will leave a big hole in the Chelsea midfield.
Meanwhile, Arsenal's problems relate to condition rather than discipline, with Aaron Ramsey, Mesut Ozil and Theo Walcott all medium- to long-term absentees.
The visitors at Stamford Bridge have had much longer to come to terms with their missing-in-action men, and so the focus will be on how Chelsea plug that hole.
Andre Schurrle looks the most likely replacement for Willian, with Jose Mourinho having the pick of Frank Lampard, David Luiz or John Mikel Obi to replace Ramires alongside Nemanja Matic.
Whoever gets the nod is likely to play a very key role in the Blues' engine room.