Thanks to the intrepid Chelsea reporter Matt Lewis we have new information on the injury statuses of both Yuri Zhirkov and Jose Bosingwa, with some good news and some bad news. I'll let Carlo Ancelotti spell it out:
Yuri Zhirkov is available to play. He will not start but I hope he will have an opportunity. Bosingwa is out but will be available for Tuesday.
Zhirkov's return has some interesting rammifications for a team that's lacked width and creativity, and he may well be included in Chelsea's starting eleven against Everton with Florent Malouda struggling for form. However Zhirkov is more of a long-term bonus - it's Bosingwa's absence that has a more obvious effect on the starting lineup tomorrow. With David Luiz unavailable thanks to the first Everton match being played while he was registered with Benfica*, Branislav Ivanovic will be fielded in the centre of defence, which means Paulo Ferreira will be playing at right back.
*This is different to being cup-tied. Fernando Torres is cup-tied, while Luiz merely cannot play in the 4th round.
Incidentally, we've also got confirmation (from that same article) that Didier Drogba will start, but whether Nicolas Anelka does is apparently an open question. It'll be interesting to see what happens should the game go to extra time, though - I'm not convinced that Drogba can handle 120 minutes of game action in general, let alone 120 minutes before a Champions League match. If I had to guess, I'd say that Nicolas Anelka will be held in reserve as a second-half substitute for Drogba. But my guesses have been pretty awful so far.