Real Madrid Castilla are focused on improving Vinicius Jr. after the striker made his debut in a Segunda B win against Las Palmas Atletico on Sunday.
Vinicius, 18, joined Madrid this summer after the club agreed a €45 million transfer from Flamengo in May 2017. He made four first-team appearances in preseason but was dropped for the UEFA Super Cup defeat to Atletico Madrid and the La Liga opener against Getafe.
With an eye toward preparing him for the future, Vinicius made his first appearance for Madrid's reserve side in the 2-0 win.
"It's not about what Vinicius can give to Castilla," Solari said. "It's about what the club, the institution, Castilla and the technical staff can give him to improve and to adapt because he will bring us a lot of happiness in the future."
Vinicius said at his presentation last month that he had "no words to describe what I feel and how happy I was wearing this jersey, being at this club that I have loved since I was born."
The forward started and played 74 minutes in his first reserve team appearance.
"You have to look after Vinicius, accompany him, and generate the best conditions possible for him to adapt," Solari said. "He is 18 and is adapting to a new country a new footballing culture, a new language and new teammates."
Julen Lopetegui said on Saturday that Vinicius would stay with Madrid this season despite interest and speculation surrounding a loan move.
"He's a player in the squad," Lopetegui said. "When he comes with us, he will have the chance to play and when not, he could play with Castilla. He is very young and just landed here."
Solari used Sergio Reguilon as an example of a player who has made the jump to the first team, as Lopetegui said the full-back will be in his squad this season.
"He has been here for many years," Solari said. "He went out on loan and he came back and now he is with the first team. The goal is for them to get to the first team, and if that's not possible then the second team.
"They are all promising young players, and some of them are realities."