According to Globo.com, West Ham formalized their interest and a proposal for Fluminense's Martinelli at some point between the beginning of the year and now. The maximum amount presented by one of the clubs was 14 million euros. All proposals occurred before Martinelli's call-up to the Brazil national team. Fluminense currently considers Martinelli to be non-negotiable due to his importance to the team and the decisive moment of the season. The club expects that new proposals may arise in the next transfer window, especially after the call-up.

According to O Dia, West Ham United are one of the teams that have submitted bids for Fluminense midfielder Martinelli, but their offers were lower than his asking price of $23 million (€20 million, £17.4 million).

An offer of approximately €12 million was submitted by West Ham for Fluminense's Matheus Martinelli. Proposals of a similar value were also made by Olympiacos, Besiktas, and teams from the Gulf. Fluminense rejected all these offers. The club values the 24-year-old Brazilian defensive midfielder at a minimum of €20 million. Martinelli's contract is valid until 2027, and the Brazilian club is reportedly looking to extend his deal until 2030. His current market value is listed by Transfermarkt as €14.00m. In the 2025/2026 season, Martinelli has made 3 appearances, providing 1 assist, in the Campeonato Carioca, and 1 appearance in Série A.