In truth, this is a dead match. Chelsea come in knowing that all they have to do is not lose by two goals against an inferior team at Stamford Bridge, and up until yesterday only one team had ever failed to win a Champions League knockout tie after winning the first match away from home (Bayern Munich's 3-2 home loss to Inter Milan made the Germans the second). FC Copenhagen are no Inter, and Chelsea aren't Bayern, either. This one isn't going to be much of a problem.
The first leg saw Chelsea beat the Danes 2-0 thanks to a pair of goals from Nicolas Anelka, and in truth they might have won by more had they made their dominance count. It was Carlo Ancelotti's first use of a flat 4-4-2 and matching the players up individually against their Copenhagen counterparts worked a treat, even though the Danes got a better towards the end of the match, getting in a few long range shots on Petr Cech's goal.
Anyway, there's not much to say. Dame N'Doye is a bit of a threat up front, to be sure, and I'd expect Stale Sobakken to be quicker to adjust Chelsea playing in a flat 4-4-2 than he was in Copenhagen, perhaps by dropping a support striker between the lines, but unless a collapse of epic proportions a la Sunderland happens, we're through to the next round. And unlike in November we're almost totally fit.
David Luiz is of course ineligible to play, meaning that we'll see a centre back pairing of John Terry and Branislav Ivanovic flanked by Ashley Cole and Jose Bosingwa. Petr Cech will start in goal. The midfield is an interesting question - Chelsea don't necessarily want an open game, so the 4-4-2 probably isn't the best choice. Instead, they'll want to clog up the centre to ensure that Copenhagen can't attack at speed, which to me calls for John Obi Mikel to be reinstated in a 4-3-3, probably alongside Ramires and Josh McEachran, who thoroughly deserves a start.
If Chelsea do indeed go 4-3-3, rumour has it that they'll drop Fernando Torres to the bench to allow Didier Drogba a start as a lone centre forward, probably flanked by Florent Malouda and Nicolas Anelka, although Salomon Kalou has made a case for himself in the starting XI as well - Kalou's movement has been superb recently.
I've given up on trying to predict starting lineups and formations, but here's what I would like to see at Stamford Bridge today:
Chelsea (4-3-3): Petr Cech; Ashley Cole, John Terry, Branislav Ivanovic, Jose Bosingwa; John Obi Mikel, Josh McEachran, Ramires; Salomon Kalou, Didier Drogba, Nicolas Anelka.
The big guns (Frank Lampard, Fernando Torres, Florent Malouda, Michael Essien) can chill out on the bench to be deployed as needed.
In all honesty I'll probably be paying more attention to the Brazil U-17 game than this match unless something strange happens in London. I think Chelsea will cruise through this without any problems at all.