Ronaldo made his professional debut for Sporting CP in 2002. He was 17 when he appeared for Sporting’s first team in a UEFA Champions League qualifying match against Inter Milan on 14 August 2002.
He entered the match as a substitute at Sporting’s José Alvalade Stadium, beginning a senior career that soon took him to Manchester United, Real Madrid, Juventus and Al-Nassr. Later that year, he made his Primeira Liga debut against Braga and scored his first league goals against Moreirense.
Detailed career records can create a small date-based confusion. Ronaldo made his first official first-team appearance in August, while his first domestic senior appearance came for Sporting CP B against Lusitânia on 1 September 2002. Both milestones belong to 2002, so the stored year is correct regardless of which senior-debut convention a source uses.