Flamengo gave a professional debut to 16-year-old Vinicius Junior on Saturday night, just days after reports said the forward had agreed a future move to Real Madrid.
Widespread reports in both Spain and Brazil said Real Madrid agreed a €45 million deal to sign Vinicius when he turns 18.
Vinicius came on for the final eight minutes of Flamengo's 1-1 draw with Atletico Mineiro in the opening game of the season but could not find a winner.
The youngster was already the top scorer and player of the tournament for Brazil at the 2017 South American Under-17 Championship in March.
Marca featured Vinicius on its front cover on Tuesday, along with Madrid's other reported planned summer capture, Theo Hernandez of Atletico Madrid.
Barcelona had previously been linked with a move for Vinicius -- dubbed the "new Neymar" -- and the club's South American representative Andre Cury was reportedly involved in preliminary talks with Flamengo and the player's agents at Traffic.
Mundo Deportivo reported that a total of €62m will be paid by Real Madrid to the various parties involved in Vinicius' future.