Barcelona v Chelsea - The History Again
In the past decade there was a period when the teams clashed four times in five seasons and now after a short break, they are paired together yet again - given their status, it's usually been in the knockout rounds, adding an edge between them.
The 2012 semi-final will be the seventh meeting in European competition in all. Chelsea were relative novices in the premier competition when they played the Catalan team in the last eight in 2000 but did have the magic of Gianfranco Zola. The Blues turned it on at Stamford Bridge to win 3-1 in the last eight.
In the Nou Camp though, Chelsea were hit by a blitz. Current Barca boss Pep Guardiola played in midfield as the Blues were swept aside 5-1 by a side with the names Figo, Kluivert and Rivaldo to the fore. Carlos Puyol played in that game and may be in the team this week.
Chelsea had to wait five years for revenge but it came in style as Jose Mourinho led the club with conviction. The team overturned a controversial 2-1 defeat in Catalonia with a stunning 4-2 victory in London.
A fair amount of bad feeling surrounded the game with Mourinho turning into something of a marked man for the Spanish press, amid allegations of referees being influenced. Inevitably, the two clubs were drawn together again a year later - again in the last 16.
This wasn't as vibrant a tie as in 2005. Barca took a 2-1 win from Stamford Bridge after left back Asier Del Horno was sent off in the first half - which provoked more ire from Mourinho. Chelsea were introduced to the sublime skills of Lionel Messi in that game.
Chelsea did force a draw in the return but only with a last minute penalty. Mourinho appeared reluctant to release Chelsea to have a real go at the opposition.
In the 2006-2007 competition the two games were in the group stages. Chelsea repeated the feat of a year earlier by scoring very late to get a draw in the Nou Camp - this time Didier Drogba made it 2-2. In London, Barcelona were beaten by a single Drogba goal and both clubs made the last 16.
The semi-final in 2009 was another rumbustious affair - no Mourinho this time but Chelsea still vented their spleen about 'assistance' to Barcelona from referees. Chelsea were desperately close to forcing a rematch of the 2008 final with Manchester United.
Only a late, late strike from Andres Iniesta sent Barca through on away goals; Michael Essien's blockbuster had given the Blues the edge after a goalless draw in Catalonia. Chelsea were left bemoaning a succession of penalty appeals that went unanswered. Guus Hiddink was angry but restrained, but Didier Drogba blew his top - a culmination of so many Chelsea near-misses in this competition.
The very first encounter in Europe was way back in 1966 in what was then the Fairs Cup. It was a semi-final which went all the way as both clubs won 2-0 on their home park.
Back in the 1960s a replay was required and Barcelona won the toss. Chelsea's return to the Nou Camp was unhappy as they were beaten 5-0.