Eight teams face elimination this week as the UEFA Champions League resumes.
Nine-time tournament winners Real Madrid, English powerhouse Manchester United, and Italian giants AC Milan will all be trying to progress through to the quarter-finals in order to earn a spot in the final at Madrid's Estadio Santiago Bernabeu.
Champions League History
The European Cup, the forerunner to the Champions League, was the brainchild of French sports journalist Gabriel Hanot.
English league champions Wolverhampton Wanderers defeated Hungarian side Honved in a 1953 exhibition match, leading Wolves' manager to rather arrogantly dub his team the "champions of the world" in the next day's newspapers.
Hanot, editor of influential French sports newspaper L'Equipe, used this as the impetus to pitch his idea for a continental-wide tournament featuring the best European clubs. UEFA, European soccer's governing body, approved Hanot's idea in April 1955 and the European Cup began in 1955-56 featuring league champions across Europe
In 1993, the European Cup was re-christened the Champions League, and in 1997-98 the tournament was expanded to include more teams, not just league champions.
The 32-team field is divided into eight round-robin groups. Teams play three games at home and on the road with three points for a win and one for a tie. The top two teams in each group at the end of the group stage advance to the next round.
After the first round, the tournament takes on a single-elimination format. The remaining 16 teams are paired off and play a home-and-away playoff. If the teams each win a game, the overall score over the course of the two games acts as the tiebreaker, followed by goals scored on the road. If the teams are still tied, a penalty shootout solves the issue.
This two-game playoff format carries over into the quarter-finals and semifinals before the last two teams standing meet in the final on May 22 in Madrid.
- 2009 — FC Barcelona (Spain).
- 2008 — Manchester United.
- 2007 — AC Milan (Italy).
- 2006 — FC Barcelona (Spain).
- 2005 — Liverpool (England).
- 2004 — FC Porto (Portugal).
- 2003 — AC Milan (Italy).
- 2002 — Real Madrid (Spain).
- 2001 — Bayern Munich (Germany).
- 2000 — Real Madrid (Spain).
- 1999 — Manchester United (England).
- 1998 — Real Madrid (Spain).
- 1997 — Borussia Dortmund (Germany).
- 1996 — Juventus (Italy).
- 1995 — Ajax Amsterdam (Netherlands).
- 1994 — AC Milan (Italy).
- 1993 — Olympique Marseille (France).
- European Cup becomes Champions League in 1993
- 1992 — FC Barcelona (Spain).
- 1991 — Red Star Belgrade (Yugoslavia).
- 1990 — AC Milan (Italy).
- 1989 — AC Milan (Italy).
- 1988 — PSV Eindhoven (Netherlands).
- 1987 — FC Porto (Portugal).
- 1986 — Steaua Bucharest (Romania).
- 1985 — Juventus (Italy).
- 1984 — Liverpool (England).
- 1983 — Hamburger SV (Germany).
- 1982 — Aston Villa (England).
- 1981 — Liverpool (England).
- 1980 — Nottingham Forest (England).
- 1979 — Nottingham Forest (England).
- 1978 — Liverpool (England).
- 1977 — Liverpool (England).
- 1976 — Bayern Munich (Germany).
- 1975 — Bayern Munich (Germany).
- 1974 — Bayern Munich (Germany).
- 1973 — Ajax Amsterdam (Netherlands).
- 1972 — Ajax Amsterdam (Netherlands).
- 1971 — Ajax Amsterdam (Netherlands).
- 1970 — Feyenoord (Netherlands).
- 1969 — AC Milan (Italy).
- 1968 — Manchester United (England).
- 1967 — Celtic (Scotland).
- 1966 — Real Madrid (Spain).
- 1965 — Inter Milan (Italy).
- 1964 — Inter Milan (Italy).
- 1963 — AC Milan (Italy).
- 1962 — Benfica (Portugal).
- 1961 — Benfica (Portugal).
- 1960 — Real Madrid (Spain).
- 1959 — Real Madrid (Spain).
- 1958 — Real Madrid (Spain).
- 1957 — Real Madrid (Spain).
- 1956 — Real Madrid (Spain).
Manchester United (England) vs. AC Milan (Italy) — United leads series 3-2
Nigel Reed: With a lead, three away goals and home advantage, United appear home and dry. Only complacency can prevent their passage, and Sir Alex Ferguson will stress to his players that they are only halfway home. Milan dominated the first 30 minutes in the opening leg and must burst out of the blocks again to make a game of it.
United may need to be patient rather than try and kill off the Italians in the first 20 minutes. Ferguson is well aware Milan is a team bristling with quality and knows how to win this competition. The Italians triumphed at Old Trafford at this stage five years ago en route to the reaching final, and they pushed United to the limit two years later as they went on to win the competition.
There will be plenty of fuss made of David Beckham's return to the Theatre of Dreams, and while he is still capable of supplying the ammunition, Milan does not have a striker to rival the form of Wayne Rooney. He scored twice in the first leg and there are plenty more goals where they came from.
Prediction: Manchester United wins game 3-1 (Manchester United win series 6-3 aggregate)
Jason de Vos: Having won the away leg 3-2, this tie should be over for the English champions. I say should be, because the one man who is absolutely vital to Manchester United's fortunes — Wayne Rooney — is an injury doubt.
Sir Alex Ferguson must be furious that Rooney picked up his injury while playing in a friendly for England, and who can blame him? With Rooney in the form of his life, United are strong candidates to win the tournament. Losing him at such a critical stage of the season is unfathomable.
Milan has injury worries too, with Alexandre Pato picking up a hamstring strain over the weekend. They will need to win by more than two goals at Old Trafford, so they will be desperate for the Brazilian to be passed fit to play.
I can't see it happening for Milan, though, regardless of whether or not Rooney plays. United just has too much in its favour to let this one slip away.
Prediction: Manchester United wins game 2-1 (Manchester United win series 5-3 on aggregate)
John F. Molinaro: Both clubs could be missing players for the second leg.
Manchester United's Wayne Rooney (knee problem) and Pato of AC Milan (thigh) are both battling injuries, and might not be able to take to the field Wednesday at Old Trafford.
The loss of Pato poses a big problem for the rossoneri right now because fellow forwards Marco Borriello and Klaas-Jan Huntelaar have hit a rough patch of form lately in Serie A.
All the media attention will be on the prodigal son, David Beckham, returning to Old Trafford, but the Englishman won't be a crucial figure for Milan. Instead, Ronaldinho has to step forward and put in the performance of his career if the Italians have any hope of advancing to the next round.
Even if Rooney doesn't play, United won't be in too much trouble because they have other players who can score. Their defence has looked suspect as of late, but I can't see the Reds conceding two goals at home.
Prediction: Manchester United wins game 1-0 (Manchester United win series 4-3 on aggregate)
Real Madrid (Spain) vs. Lyon (France) — Lyon leads series 1-0
Reed: Madrid will host the Champions League final, but the hometown team must improve if it is to be involved in the climax of the European season. Cristiano Ronaldo and his chums were decidedly second best in the series opener in France and there is huge pressure for Real to deliver in front of their own fans.
Lyon's slim advantage is no fluke — they may have been outplayed in the first leg in terms of possession, but they took the game to Madrid and were rewarded for their enterprise. The Frenchmen don't have the big stars, but they do have a system that works for them — one they understand and trust.
Madrid, though, are irresistible and almost unbeatable at the Bernabeu Stadium. You get the feeling it won't take them long to cancel out the deficit even without the suspended Xabi Alonso and Marcelo. Real have so many potential routes to goal, Lyon goalkeeper Hugo Lloris will need to play the game of his life for Lyon to hang on to their lead.
Prediction: Real Madrid wins game 2-0 (Real Madrid wins series 2-1 aggregate)
De Vos: Madrid's failure to score in France could come back to haunt them. They have plenty of firepower though, and they are very capable of winning the home leg of this tie by two or three goals.
That being said, Lyon is not a pushover. They managed to blank the galacticos in France, and they will be happy to go to Madrid knowing that a draw will see them through.
On paper, Madrid is a much more talented team. They have wonderfully skilled individuals, and if they all perform to their abilities, they will be a handful for Lyon.
I expect Madrid to win this game, but if Lyon can stem the tide in the first half and frustrate Madrid, they will have confidence that they can hold out for a result that will see them through to the next round.
Like the Porto-Arsenal fixture, I have a feeling that this one won't go exactly according to plan for the favourites.
Prediction: Real Madrid wins game 2-1 (Lyon wins series on away goals)
Molinaro: Los blancos are riding high after coming from behind to beat Sevilla 3-2 on the weekend, a result that propelled them into a tie for first place with Barcelona in Spain's la liga.
The Spaniards have been scoring for fun lately, and there's no reason to believe that trend will end, even if star striker Karim Benzema will miss Wednesday's clash with his old club Lyon due to a groin strain
Argentine Gonzalo Higuain has been on fire for Madrid, and he'll ask serious questions of Lyon's defence at the Bernabeu. Midfield creator Xabi Alonso will sit out the game due to suspension, but his absence shouldn't slow down Madrid too much, especially with Kaka and Cristiano Ronaldo in the lineup.
Madrid spent heavily on replacements in the off-season with the intention of winning their 10th Champions League title this year. The fact that the final will be staged at their home stadium provides them with even more motivation. Lyon is a capable team and did well to win the first leg, but look for Madrid to pour on the style this week and bury the Frenchmen.
Prediction: Real Madrid wins game 3-0 (Real Madrid wins series 3-1 on aggregate)
Fiorentina (Italy) vs. Bayern Munich (Germany) — Bayern Munich leads series 2-1
Reed: Fiorentina is not among Europe's giants, but it may be the only Italian team left standing when the round of 16 is complete. With Milan facing a mountainous task at Old Trafford and Inter far from convincing against Chelsea, it may be la viola's time to shine.
Fiorentina were genuinely unlucky to lose the first leg — more than matching their German opponents before Miroslav Klose's suspiciously offside-looking late winner was allowed to stand. Cesare Prandelli's men will be desperate to avenge what they saw as a grave injustice.
Man for man, Bayern looks the stronger team and hammered a poor Juventus outfit on their last visit to Italy. Arjen Robben caused Fiorentina problems in the first leg and they'll have to keep him quiet to have a chance in the decider in Florence.
Prediction: 2-2 draw (Bayern Munich wins series 4-3 on aggregate)
De Vos: Given the form of both teams heading into the first game of this tie in Munich, it was reasonable to assume that the Germans would win comfortably. That wasn't the case, and if not for the help of numerous dubious refereeing decisions, Munich could have lost the home leg.
As it stands, they head to Italy with a 2-1 lead, knowing that, just like Porto, an away goal puts them firmly in the driver's seat.
Bayern is a better team than Fiorentina; they have much more going for them offensively, and they have been on a tremendous run of form this season. It is fair to say that they will expect to progress into the next round of the tournament, but it might not be as easy for them as they would like.
Prediction: 1-1 draw (Bayern Munich wins series 3-2 on aggregate)
Molinaro: This is a classic tale of two teams headed in opposite directions.
While Bayern is undefeated in its last 18 games, Fiorentina has won just one of its last nine Serie A matches and has gone 17 games since registering its last shutout.
The Stadio Franchi is an intimidating place to visit, so the Germans can expect a hostile reception, which should give Fiorentina a bit of a psychological edge. What's more, Bayern will be without key defender Martin Demichelis (knee injury), while left-back Diego Contento could also miss the game due to injury.
The news isn't all bad for Bayern, though: wingers Arjen Robben and Frank Ribery are set to return to the starting lineup, and should give Fiorentina's brittle defence all it can handle.
Prediction: 1-1 draw (Bayern Munich wins series 3-2 on aggregate)
Arsenal (England) vs. FC Porto (Portugal) — Porto leads series 2-1
Reed: Porto has a slim lead, but it is too slender for the Portuguese champions to stop Arsenal marching into the quarter-finals. While history doesn't tell you everything, there's more than enough evidence to suggest a comfortable passage for the Gunners.
Porto is one of Europe's strongest home teams but simply doesn't travel well. They have never won in 13 attempts on English soil and were thrashed 4-0 at Arsenal 18 months ago. Arsene Wenger's team is playing well these days, particularly at the Emirates Stadium, where they won all three games to top Group H in the first round.
Arsenal must overcome that first-leg deficit of course, but it is difficult to imagine the visitors being able to maintain a clean sheet. Only Chelsea have left North London without conceding a goal this season, and Sol Campbell's unlikely away goal from the first leg could prove decisive.
Prediction: Arsenal wins game 2-0 (Arsenal wins series 3-2 aggregate)
De Vos: Porto leads this tie, having won the home leg 2-1. With Arsenal picking up a crucial away goal, it is almost imperative that Porto score a goal at the Emirates Stadium.
My head tells me that, given the form that Arsenal have exhibited of late, the Gunners should get the job done on home soil. However, I have a sneaky suspicion that there is a twist to come in this one.
Arsenal has a slight advantage because of their away goal, but that will change if Porto can get on the board themselves. Porto's players have already said they are not going to go into a defensive shell and protect their lead, and that is the right mentality. Arsenal are fragile defensively, and a clean sheet on home soil is by no means a given.
The game will be won or lost in midfield. Cesc Fabregas is a doubt for Arsenal, and if he is not available or plays at less than 100 per cent, then the advantage shifts in Porto's favour.
Prediction: Arsenal wins game 2-1 (Series tied 3-3 on aggregate; Porto goes through after penalties)
Molinaro: Everything points to a victory for the Gunners in this one.
Porto has lost its last six matches in London, they have fallen 11 points behind rivals Benfica in the Portuguese league, and they enter this game having conceded a crucial goal at home against the Gunners in the first leg.
Porto has a habit of grinding out results, however, and I have a feeling they'll do the same this week.
Arsenal will have to cope without injured captain Cesc Fabregas (thigh injury). The Gunners aren't the same team without him — the Spanish creator is one of the best midfielders in the game and pulls the playmaking strings for Arsenal. Without him, they're a lesser team.
Arsenal will also be without defender William Gallas, which means aging veteran Sol Campbell will be in the lineup. Look for Porto to exploit the Gunner's defence, especially on the counter-attack and on set pieces.
Prediction: Porto wins game 1-0 (Porto wins series 3-1 on aggregate)