The beggining

After Messi was diagnosed with a growth hormone deficiency, his parents couldn't afford his medical treatment, which cost $ 900 a month. Carles Rexach, the sporting director of FC Barcelona, had been made aware of his talent as Messi had relatives in Lleida, and Messi and his father were able to arrange a trial with the team. Messi and his father moved to Barcelona where Messi enrolled in the club's youth academy.

Messi played in Barcelona's junior Infantil B and Cadete B & A teams from 2000 to 2003. In season 2003-04 Messi debuted in five different teams - he started one match in Juvenil B and got promoted to Juvenil A. On 29 Novebmer 2003 Messi went in FC Barcelona C team and for FC Barcelona B on 6 March 2004.

On 16 October 2004 Frank Rijkaard gave Messi, his league debut against RCD Espanyol.

2005 - 06 season

On 16 September, for the second time in three months, Barcelona announced an update to Messi's contract; this time it was improved to pay him as a first team member and extended until June 2014. Messi netted six goals in 17 league appearances, and scored one Champions League goal in six.

2006 - 07 season

In that season Messi established himself as a regular first team player, scoring 14 times in 26 matches. Towards the end of the season he began finding the net more often; 11 of his 14 league goals for the season came from the last 13 games.On 18 April 2007, he scored two goals during a Copa del Rey semi-final against Getafe CF, one of which was very similar to Maradona's famous goal against England at the 1986 World Cup in Mexico, known as the Goal of the Century. Against RCD Espanyol Messi also scored a goal which was remarkably similar to Maradona's 'Hand of God' goal.

2007 - 08 season

On 27 February, Messi played in his 100th official match for Barcelona against Valencia CF. Messi scored 6 goals and provided 1 assist during the Champions League that season, as Barcelona were knocked out in the semi-finals, to the eventual winners Manchester United. When the season was over Messi had managed to score 16 goals and assisted 13 times in all competitions.

2008 - 09 season

During this season Messi placed second in the 2008 FIFA World Player of the Year awards with 678 points and third in the 2008 IFFHS World's Best Playmaker Award for the second consecutive year. Messi scored his first hat-trick of 2009 in a Copa del Rey tie against Atletico Madrid which Barcelona won 3-1.

As Barcelona's season was drawing to a close, Messi scored twice to cap a 6-2 win over Real Madrid at the Santiago Bernabeu. This victory meant Barcelona had won the Copa del Rey, La Liga and Champions League in the one season, and was the first time a Spanish club had ever won the treble. Messi finished the season with 38 goals and 18 assists in all competitions.

2009 - 10 season

On 18 September, Messi signed a new contract with Barcelona, running until 2016 and with a buy-out clause of € 250 million included. Messi scored a hat-trick against Valencia CF in a 3 - 0 home win, and finally he scored another hat-trick against Real Zaragoza in a 4-2 away win, becoming the first Barcelona player to score back-to-back hat-tricks in La Liga.

He played his 200th official match for Barcelona against CA Osasuna on 24 March 2010. For the first time in Messi's career he scored four goals in a single match agains Arsenal in the Champions League quarter-final second leg.

He finished the season with 47 goals in all competitions.

2010 - 11 season

In his first start of the season Messi scored a hat-trick in a 4-0 victory over Sevilla FC in the Supercopa de Espana. On 5 February, Barcelona broke the record for most consecutive league wins with 16 victories after they defeated Atletico Madrid.

In the first leg of the Champions League semi-finals, Messi scored twice against Real Madrid. Messi finished the 2010-11 season with 53 goals and 24 assists in all competitions combined.

2011 - 12 season

In the start of 2011-2012 season, Messi lifted the Spanish Supercup with Barcelona. In August, Messi became the second highest goalscorer surpassing Laszlo Kubala on 194 goals, being behind only to Cesar Rodriguez on 232 goals in all official competitions.

On his 200th La Liga appearance, Messi scored four goals against Valencia CF in a 5-1 win. On 25 May, he scored again in the 2012 Copa del Rey Final, helping Barcelona win their 26th Spanish Cup title, and increasing his seasonal goalscoring record to an unmatched 73 goals in all competitions.

Messi finished the season with 73 goals and 29 assists in all club competitions, with more goals and assists than any other player.

2012 - 13 season

On 7 January 2013 odds-on favourite[172] Messi won the 2012 FIFA Ballon d'Or, again beating Cristiano Ronaldo into second place with team-mate Andres Iniesta third. In doing this, Messi became the only player in history to win the Ballon d'Or four times.

On 17 March 2013, in a match against Rayo Vallecano, Messi wore the captain's armband for the first time in an official match for Barcelona, taking over after Andrés Iniesta was substituted.

Messi scored Barcelona's second goal at Celta de Vigo for the 19th consecutive La Liga game, and became the first footballer in history to score in consecutive matches against every team in the league.