Carlo Ancelotti was full of praise for Rayan after the teenager produced a complete and mature performance in Brazil's commanding 3-0 victory over Scotland on Wednesday, as the Bournemouth forward made World Cup history in the process.
Having entered cautiously as a substitute in the win over Haiti — after Raphinha was forced off with the hamstring injury that has since ended his tournament — the 19-year-old seized his opportunity to start and was one of the Selecao's standout performers at the Hard Rock Stadium in Miami.
'He did a complete job,' Ancelotti told reporters afterwards. 'Offensive and defensive. I am satisfied with the game he played. He is young, he has maturity and he works hard. Nobody knows the level he can reach.'
In becoming the first teenager to start a World Cup match for Brazil since Marco Antonio lined up at left-back for the quarter-final against Peru in 1970, Rayan showed no sign of the occasion overwhelming him.
Rayan's role in Brazil's goals
His influence on the game was felt throughout, and directly contributed to the first two goals.
For the opener, his pressing of Scott McKenna forced an error — the ball fell kindly to Vinicius Junior, who rounded goalkeeper Angus Gunn to score his second goal of the tournament.
The second goal began with another of Rayan's purposeful forays, as a combination with Bruno Guimaraes ended with the youngster being dispossessed inside the area, but Matheus Cunha recovered possession, Danilo won a duel and Guimaraes found Vinicius Junior for his second of the night.
His only blemish of the evening came in first-half stoppage time, when Lucas Paqueta released him and he skipped past Andy Robertson to find himself clean through on goal — only to shoot straight at Gunn.
Why Rayan was picked ahead of Luiz Henrique
With Raphinha sidelined, Ancelotti faced a choice between Luiz Henrique — who had the stronger run of form over the months leading into the tournament — and Rayan, whose performances for Bournemouth in the Premier League had been nothing short of sensational in a short space of time.
The display against Scotland illustrated why the boss went with the younger option.
Rayan's ability to combine with teammates and willingness to make runs into the penalty area made him the better fit for a system in which Cunha drops deeper to create space, allowing both Vinicius Junior and the right-sided forward to operate closer to goal.
A meteoric rise from Vasco da Gama to Brazil's World Cup squad
Rayan's move from Vasco da Gama to Bournemouth in January was met with scepticism in some quarters, but the transfer proved inspired. With Antoine Semenyo having departed for Manchester City, Rayan arrived at Vitality Stadium with ample opportunity to play regularly and develop quickly.
He did not waste it — five goals and two assists in 15 appearances contributed directly to Bournemouth's first ever European qualification, earning him a call-up to the final Brazil World Cup squad even as the group appeared settled.
His introduction had already made an impression. In a March friendly against Croatia, he and Endrick combined to cause problems in the closing stages, and Rayan came close to a first Brazil goal only for a fine Dominik Livakovic save to deny him.
He would not have to wait long — he scored in the 6-2 farewell victory over Panama in late May, the Selecao's final match on home soil before departing for North America.
Against Scotland, on the grandest stage of all, he showed exactly why that faith was well placed.