Preview: As much as this encounter is a massive match in its own right, it is hard to discuss without constantly referring back to the infamous meeting of Chelsea and Barcelona at the same semi-final stage of the Champions League three years ago.
It is not surprising then that much of the pre-match talk has been taken up by the controversial element that accompanied the second-leg at Stamford Bridge in 2009. Yet, it is perhaps the nature of the two matches themselves that is most relevant when considering how this tie will pan out.
Refereeing decisions aside and despite Barcelona displaying great tenacity to fight till the end before getting the crucial goal, the undeniable fact from the sides' last matchup was that Barcelona found Chelsea one of their toughest opponents of the Pep Guardiola era.
It is a fact with which interim Chelsea coach Roberto Di Matteo is well aware.
They don't like to play against us, results in the past have shown that, Di Matteo said, according to the official Chelsea website. The way we play is difficult for them to play against. We respect each other, but there will be two teams playing against each other and we will try to cause them problems.
Yet, while the key players from that Chelsea team remain, they are all now showing full signs of their long careers in their legs.
That Chelsea team was particularly difficult for Barcelona because of the Blues' dogged defensiveness and ability to give nothing away, but there is now more than a sense that the Blues will give you a chance. And that is something that could be fatal against Barcelona.
As Chelsea has gotten weaker, Barcelona have gotten even stronger in the intervening years. Lionel Messi is flourishing in a new role and the additions of Alexis Sanchez and Cesc Fabregas, as well as the developing Issac Cuenca, Cristian Tello and Thiago Alcantara have given the Catalan giants an increased strength in depth.
Yet, as Guardiola acknowledges, Chelsea may not be capable of being consistently dominating as they once were, but they can still give any side a rough night in a one-off match.
Perhaps they haven't had the capacity to maintain their consistency throughout a long competition, but in a shorter one they are one of the most dangerous sides, Guardiola said, according to the official Barcleona website.
It is that fact that makes the first-leg at Stamford Bridge on Wednesday absolutely crucial.
Team News: Chelsea will be without David Luiz after the Brazilian defender was taken off with a hamstring injury in the FA Cup semi-final against Tottenham on Sunday. Gary Cahill will step-in. Branislav Ivanovic will return at right-back after serving a domestic suspension.
Di Matteo is keeping his cards close to his chest about whether he will select Didier Drogba or Fernando Torres up-front. Despite his past success against Barcelona and the goal he scored at the weekend, speculation suggests that Torres will get the nod.
Although Xavi was taken off at the weekend with a persistent achilles injury, it would be a major surprise if he were not in the Barcelona starting lineup.
Prediction: Chelsea know that this tie and in particular this home-leg represents the last hurrah for many of their players and they will be putting everything into trying to get a positive result. However, with Barcelona's quick, incisive passing and incessant pressing Barcelona could be primed to expose Chelsea's weaknesses.
Chelsea 1-2 Barcelona