<P> A lifelong supporter of Newell's Old Boys, Messi joined the Rosario club when he was six years old . During the six years he played for Newell's, he scored almost 500 goals as a member of "The Machine of' 87", the near - unbeatable youth side named for the year of their birth, and regularly entertained crowds by performing ball tricks during half - time of the first team's home games . However, his future as a professional player was threatened when, at age 10, he was diagnosed with a growth hormone deficiency . As his father's health insurance covered only two years of growth hormone treatment, which cost at least $1,000 per month, Newell's agreed to contribute, but later reneged on their promise . He was scouted by Buenos Aires club River Plate, whose playmaker, Pablo Aimar, he idolised, but they were also unable to pay for his treatment due to the country's economic collapse . </P> <P> As the Messi family had relatives in Catalonia, they sought to arrange a trial with Barcelona in September 2000 . First team director Charly Rexach immediately wanted to sign him, but the board of directors hesitated; at the time it was highly unusual for European clubs to sign foreign players of such a young age . On 14 December, an ultimatum was issued for Barcelona to prove their commitment, and Rexach, with no other paper at hand, offered a contract on a paper napkin . In February 2001, the family relocated to Barcelona, where they moved into an apartment near the club's stadium, Camp Nou . During his first year in Spain, Messi rarely played with the Infantiles due to a transfer conflict with Newell's; as a foreigner, he could only be fielded in friendlies and the Catalan league . Without football, he struggled to integrate into the team; already reserved by nature, he was so quiet that his teammates initially believed he was mute . At home, he suffered from homesickness after his mother moved back to Rosario with his brothers and little sister, María Sol, while he stayed in Barcelona with his father . </P> <P> After a year at Barcelona's youth academy, La Masia, Messi was finally enrolled in the Royal Spanish Football Federation (RFEF) in February 2002 . Now playing in all competitions, he befriended his teammates, among whom were Cesc Fàbregas and Gerard Piqué . After completing his growth hormone treatment aged 14, Messi became an integral part of the "Baby Dream Team", Barcelona's greatest - ever youth side . During his first full season (2002--03), he was top scorer with 36 goals in 30 games for the Cadetes A, who won an unprecedented treble of the league and both the Spanish and Catalan cups . The Copa Catalunya final, a 4--1 victory over Espanyol, became known in club lore as the partido de la máscara, the final of the mask . A week after suffering a broken cheekbone during a league match, Messi was allowed to start the game on the condition that he wear a plastic protector; soon hindered by the mask, he took it off and scored two goals in 10 minutes before his substitution . At the close of the season, he received an offer to join Arsenal, his first from a foreign club, but while Fàbregas and Piqué soon left for England, he chose to remain in Barcelona . </P> <P>--Barcelona's then assistant coach Henk Ten Cate on Messi's first - team debut . </P>

When did lionel messi started his football career