The 2006-2007 season was an overall unsuccessful time for FC Barcelona in almost all competitions. Although the team managed to snatch the Supercopa de España, and finish second in the domestic league, a lot more was expected from the team that had been European champion. It started with the team's defeat at the final of the 2006 FIFA Club World Cup Final near the end of 2006, and the team did worse in 2007. This was the first of two bad seasons for the club, which led to great changes in the roster and direction. This also marks both the last season FC Barcelona wore a jersey without a sponsor and the first time a sponsor appeared in it: UNICEF (this was a non-commercial agreement).

Carles Puyol, Lionel Messi, and Ronaldinho were selected as part of FIFPro World XI for the 2006–07 season.

Source: FC Barcelona, players' Wikipedia articles, ESPN (for appearances and goals) and footballdatabase.com (for EU passport)
Ordered by most frequent start and position on pitch (from back right to front left).

Barcelona (English /bɑrsɨˈloʊnə/, Catalan: [bərsəˈɫonə], Spanish: [barθeˈlona]) is the capital of Catalonia and the second largest city in Spain, after Madrid, with a population of 1,621,537 within its administrative limits on a land area of 101.4 km² (39 sq mi). The urban area of Barcelona extends beyond the administrative city limits with a population of between 4,200,000 and 4,500,000 within an area of 803 km² (310 sq mi), being the sixth-most populous urban area in the European Union after Paris, London, the Ruhr, Madrid and Milan. About five million people live in the Barcelona metropolitan area. It is also Europe's largest metropolis on the Mediterranean Sea. It is the main component of an administrative area of Greater Barcelona, with a population of 3,218,071 in an area of 636 km² (density 5,060 hab/km²). It is located on the Mediterranean coast between the mouths of the rivers Llobregat and Besòs and is bounded to the west by the Serra de Collserola ridge (512 m/1,680 ft).

Founded as a Roman city, Barcelona became the capital of the County of Barcelona. After merging with the Kingdom of Aragon, Barcelona became one of the most important cities of the Crown of Aragon. Besieged several times during its history, Barcelona has a rich cultural heritage and is today an important cultural centre and a major tourist destination. Particularly renowned are the architectural works of Antoni Gaudí and Lluís Domènech i Montaner, which have been designated UNESCO World Heritage Sites. The headquarters of the Union for the Mediterranean is located in Barcelona. The city is known for hosting the 1992 Summer Olympics as well as world-class conferences and expositions, including the 1888 Exposición Universal de Barcelona, the 1929 Barcelona International Exposition (Expo 1929), the 2004 Universal Forum of Cultures, and the 2004 World Urban Forum.

Lionel Andrés Messi (Spanish pronunciation: [ljoˈnel anˈdɾes ˈmesi], born 24 June 1987) is an Argentine footballer who plays in La Liga for FC Barcelona and is the captain of the Argentina national team, mainly as a forward.

By the age of 21, Messi had received Ballon d'Or and FIFA World Player of the Year nominations. The following year in 2009 he won both the Ballon d'Or and FIFA World Player of the Year, and won the inaugural FIFA Ballon d'Or in 2010 and 2011. He also won the 2010–11 UEFA Best Player in Europe Award. Messi is the fourth football player to win three Ballons d'Or, after Johan Cruyff, Michel Platini and Marco van Basten and the second player to win three consecutive Ballons d'Or, after Michel Platini. His playing style and small stature have drawn comparisons to Diego Maradona, who himself declared Messi as his "successor".

Messi has won five La Liga titles and three Champions League titles. In 2012, Messi made UEFA Champions League history by becoming the first player to score five goals in one match, in a 7–1 win against Bayer Leverkusen. With two goals in the next round against A.C. Milan, he matched José Altafini's record of 14 goals in a single UEFA Champions League/European Cup season. He also became the first player to top-score in four successive European Champion Clubs' Cup campaigns. He set the world record for most goals scored in a season during the 2011–12 season, with 73 goals.

Cristiano Ronaldo dos Santos Aveiro,OIH, (born 5 February 1985), commonly known as Cristiano Ronaldo, is a Portuguese footballer who plays as a winger or striker for Spanish La Liga club Real Madrid and is the captain of the Portuguese national team. Ronaldo became the most expensive footballer in history after moving from Manchester United to Real Madrid in a transfer worth £80 million (€93.9 million/$131.6 million). In addition, his contract with Real Madrid, in which he is paid €12 million per year, makes him one of the highest-paid footballers in the world, and his buyout clause is valued at €1 billion as per his contract.

Ronaldo began his career as a youth player for Andorinha, where he played for two years, before moving to C.D. Nacional. In 1997, he made a move to Portuguese giants Sporting Clube de Portugal. Ronaldo's precocious talent caught the attention of Manchester United manager Alex Ferguson, who signed him for £12.24 million (€15 million) in 2003. The following season, Ronaldo won his first club honour, the FA Cup. He also played at Euro 2004 with Portugal and scored his first international goal in the opening game of the tournament against Greece, in addition to helping Portugal reach the final. He was featured in the UEFA Euro All-Star Team of this competition.