Champions League preview: Barcelona v Chelsea
Reigning champions Barca trail Chelsea 1-0 following their surprise defeat in the first leg at Stamford Bridge last Wednesday.
Chelsea have been well below their best for much of the season, and few observers gave them a chance of upsetting Pep Guardiola's team.
The home side did indeed see little of the ball during the 90 minutes, but somehow snatched a goal through veteran striker Didier Drogba just before the half-time whistle.
Alexis Sanchez and Pedro Rodriguez hit the woodwork for Barca, and Chelsea goalkeeper Petr Cech was called upon several times to deny the visitors.
Given the prize on offer, it would appear the coaches of both teams are prioritising Wednesday's return fixture over domestic considerations.
Chelsea's interim manager Roberto Di Matteo made a raft of changes for his team's visit to Arsenal in the English Premier League on Saturday, a match which ended in a 0-0 draw.
Meanwhile, Barca coach Pep Guardiola brought in Christian Tello and Thiago Alcantara, while leaving out Alexis Sanchez and Cesc Fabregas, for the Clasico at home to Real Madrid.
Jose Mourinho's Real emerged 2-1 winners from the crunch fixture, to open up a seven-point lead at the top of La Liga.
Those results mean Chelsea will be hard pressed to earn a place in next season's Champions League through a top-four finish, while Barca have effectively surrendered their Liga crown to Real.
So, with earning a place in the Champions League final now paramount to both clubs, this week's match looms as season-defining.
Drogba sat out the Arsenal draw with a minor knee complaint, but is likely to replace Fernando Torres in the Chelsea attack.
Ashley Cole, Frank Lampard, Raul Meireles, Juan Mata and John Obi Mikel could all return to the starting line-up, with Ryan Bertrand, Florent Malouda, Oriol Romeu, Daniel Sturridge and Michael Essien likely to step aside.
For Barca, Sanchez and Fabregas should come in for Tello and Alcantara.
Pedro and centre-back Gerard Pique, the latter reportedly out of favour with Guardiola, are also in contention for a place in Barca's starting 11.