Reinier has been linked with a €30million transfer to Madrid this month – reports suggesting the 17-year-old attacker will sign after his 18th birthday on January 19.
Asked about his future, a tight-lipped Reinier told reporters: "Let's wait and see."
Reinier – compared to Brazilian great and former Madrid star Kaka – scored six goals in 14 appearances in Brazil's Serie A last year as Flamengo won the title.
The in-demand teenager also featured in Flamengo's 2019 Copa Libertadores triumph.
Flamengo team-mate Filipe Luis, who arrived from Atletico Madrid last year, told Marca: "He has surprised me at 17 in that he always chooses the correct option.
"When he has to pass, he passes, he plays with his head up. It really is a great signing, I congratulate Real Madrid."
"He isn't 100 per cent ready," Filipe Luis said. "He is 17 years old, but has potential and a great future. Nobody is ever ready for a leap so vast at that age, but in the future he will be a great signing."
"I remember Kaka because he played with his head up, and he was lethal in the area," Filipe Luis added. "Reinier has even more quality than Kaka with his back to goal. Time will tell whether or not he is like Kaka."