During the 2003-2004 season,his fourth with Barcelona,Messi played pre-season competitions with the Juveniles B,he played one official game with them before being promoted up to Juveniles A,where he scored 18 goals in 11 games.Messi was then one of those few players who were called up in the first team during international break.
French winger Ludovic Guily said " He destroyed us all.They were kicking him all over the place to avoid being ridiculed by this kid,he just got up and kept on playing.He would dribble past four players and score a goal. Even the team's starting centre-backs were nervous. He was an alien."
At the age of 16 years 4 months and 23 days,Messi made his first team debut when he came in as a substitution in a friendly against FC Porto.After his first training session with the senior team,Barca's bew star player Ronaldinho Gaucho told his teammates that he believe the 16 y/o would become better than himself.Ronaldinho soon befriended Messi,whom he called "Little Brother".
To gain further experience,Messi joined Barcelona C in addition to Juveniles A,playing his first game for the third team on 29th November.He helped save them from the relegation zone of the Terecera Division,scoring 5 goals in 10 games,including a hat-trick in 8 minutes during a Copa Del Rey match while man marked by Sevilla's Sergio Ramos.
A month later he made his debut for Barcelona B. He played 5 matches for Barca B but didn't scored.Physically he was weaker than his opponents who were often much older and taller than him. So he started working on increasing muscle mass and overall strength in order to shake off defenders. In that season he had scored 36 goals in all official competitions.
In 2004-05 season he had been called up in the first team again under the manager Frank Rijkaard after being requested by first team players.So Messi made his league debut on 16th October,against Espanyol where he came in as substitution.At the age of 17years 3 months 22days, he was the youngest player to represent Barcelona. He scored his first senior goal in 1st May 2005 against Albacete,from an assist by Ronaldinho,which made him the youngest ever scorer for the club.
In my entire life,I have never seen a player of such quality and personality at such a young age,particularly wearing the 'heavy' shirt of one of the world's great clubs.
- Fabio Capello
On 24th June 2005,his 18th Birthday,Messi signed his first contract which made him a Barca player until 2010, with a buyout clause of €150 million. In that year Italian club Inter Milan wanted to buy Messi and would triple up his wages. According to then president Joan Laporta,it was only that time club faced the real risk of losing Messi. On 16th September his contract was updated and got extended till 2014.
By the time Messi has also started to establish himself as the first choice winger,forming an attacking trio with Ronaldinho and Samuel Eto'o. In the process he started in many games,which includes a match where he scored his first Champions League goal. On 7th March 2006,against Chelsea he suffered a torn hamstring and was out for the whole season.
In 2006-07 campaign he scored 17 goals in 36 games across all competitions. However,he continued to be plagued by major injuries,a metatarsal fracture on 12th November2006, kept him out of action for 3 months. Meanwhile Barcelona who were the defending champions in Champions League got knocked out in Round 16 without Messi. During the later part of the league season Messi came back and scored 11 goals in 13 games.
On 10th March 2007,he scored his first ever hat-trick for Barcelona that's too El Classico,the first player to do so in 12 years,equaling every goal Real Madrid scored in that match and ending the match 3-3. It was literally Lionel Messi vs Real Madrid. His importance in the club increased tremendously and he got a new contract within a week, which greatly increased his wages.
On 18th April 2007 he scored a goal which was remarkably similar to Maradona's goal in 1986 WC. Messi collected the ball in the halfway,ran around 66 yards,dribbled past 5 defenders before scoring an angled finish similar to Maradona's one.Recently this goal has been termed as the best ever goal in the club history of FC Barcelona.
As Messi continued his individual ruse,Barcelona flattered in both Copa Del Rey and La liga,while Leo Messi was rested.
Meanwhile Ronaldinho also lost his form and 20 year old Messi became the Barca's new star player.
His efforts also earned him award recognitiom where journalista voted him 2nd in the Ballon d'or voting just behind Kaká. It was just the beginning of a kid who is all set to gift many magical moments to the football world which will be cherished and remembered forever.