Neymar and Vinicius Junior could play "in any team in the world" according to Casemiro, but the Real Madrid midfielder said it would be down to national team coach Tite to decide whether they can play together for Brazil.
As the Selecao prepared for friendly matches against Panama and Czech Republic, Casemiro expressed his admiration for Paris Saint-Germain forward Neymar and his Madrid team-mate Vinicius, both of whom are ruled out of international duty by injuries.
While Neymar has made 96 appearances for Brazil in the nine years since making his bow, Vinicius has yet to be handed his full international debut.
But Casemiro feels the 18-year-old's recent form for Madrid, where he has made eight LaLiga starts and scored two goals in 2018-19, put him in the same bracket as Neymar.
"We started talking about Neymar here," Casemiro told reporters. "Let's spend the whole afternoon talking about him.
"For me, Neymar's in the top three and has everything to be the best in the world. In the last two months Vinicius played at a high level, at a level of one of the best in the world.
"What he's producing at Real was not normal, for someone who's 18 years old. Being bold in the shirt of Real Madrid is not easy."
Tite has the likes of Everton forward Richarlison and West Ham winger Felipe Anderson in his squad to face Panama and Czech Republic, but Casemiro knows there will be some tough decisions to make when Neymar and Vinicius return to fitness.
Neymar is recovering from a fractured metatarsal while Vinicius has damaged ankle ligaments, and Casemiro backed the pair to flourish upon their comebacks.
"We're talking about two great players, two players who are exceptional," said Casemiro.
"It is up to the coach to talk about whether they can play together or not. There's no doubt they are great players.
"Of course, they can play in any team in the world."
Brazil's match against Panama takes place in Portugal on Saturday, while the clash with Czech Republic is on Tuesday in Prague.