Arsenal is missing its defense. Let me not understate the obvious. Anytime Mikael Silvestre is brought on, it is not just dire. It is a crisis.
We do not have Gallas, Clichy, Djorou, Sagna, Almunia and now Gibbs possibly out with a groin problem. In fact, Silvestre will probably be shunted to the left and Song will pair up with Toure as center back. Eboue will see duty on the right. The midfield will be manned by Nasri, Arshavin, Fabregas, and Walcott. Up top lies Adebayor. His choice of attacking partner should be a toss up between Eduardo and Van Persie. If it were left to me then Eduardo should start because he is a better opportunist. In fact, his fox in the box reputation will have to serve him well.
The immediate problem Arsenal's makeshift defense faces is to limit the damage that Nicolas Anelka, Frank Lampard, and Didier Drogba can do up front. In fact, it was the subservient play of Anelka that set up Drogba and Lampard's goals against Liverpool.
Chelsea's defense has been criticized for conceding 7 goals in 2 games but it should not obfuscate the fact that Chelsea's goals have also come from Ivanovic and Alex who have come up big on set pieces. Alex's place will be taken by Terry returning from suspension. Terry scores goals on an average similar to that of Gallas, the best scoring Arsenal defender, who unfortunately is out for the season. One also has to pay close attention to Michael Essien whose long range efforts have sunk the Gunners before.
The bottom line is that Arsenal's attack has to capitalize on its chances that its superior midfield creates because the defense does not have a Joleon Lescott or Matthew Taylor to offset the pressure of a less than stellar day from Adebayor, Fabregas or Arshavin.