Chelsea interim manager Roberto Di Matteo has admitted that his side will need to produce two "perfect" games if they are to progress past Barcelona in the Champions League.
The Blues meet Barca in their last-four tie at Stamford Bridge on Wednesday, with the Catalan giants considered heavy favourites to qualify for the final.
Di Matteo has acknowledged the unenviable challenge that Chelsea face but believes that their recent good form has given them confidence ahead of tomorrow's first leg.
"It's fair to say we need two perfect games," Di Matteo said.
"But I think, also, that the fact we've been performing very well in the last six weeks gives us the belief we can produce two perfect games in this match.
"It's the biggest challenge for any manager to play against the best team in the world, but for every player as well, to be able to compare themselves against one of the top teams in the world."
Barca are 4/6 favourites with the bookmakers to win in London tomorrow, with Chelsea available at odds of around 4/1.