Rosa, 17, is a defensive midfielder who represents Brazil at youth level. He was part of the Brazil side that won the 2019 FIFA U-17 World Cup.
He has yet to make his first team debut for Gremio but is considered a big hope for the future.
Gremio had planned to promote Rosa to their first team squad this season before the Coronavirus pandemic postponed the plan.
According to UOL Esporte, Gremio received contact from the City Football Group, Man City’s parent company.
And there is optimism among those involved in talks of a deal going through, even though officially Gremio deny negotiations.
Rosa joined Gremio from Vitoria as part of a deal that saw Wallace Reis move to the Salvador club.