Martinelli, 21, has scored five goals in 13 Premier League appearances this season, while Firmino, 31, misses out despite six goals in 12 games.
Brazil start their campaign against Serbia on 24 November, followed by games against Switzerland and Cameroon in Group G.
There are 12 Premier League players in Tite’s squad overall, with Liverpool’s Alisson and Manchester City’s Ederson to battle for the starting goalkeeper’s spot.
Chelsea defender Thiago Silva has been named, while the midfielders include Manchester United’s Casemiro and Fred, Newcastle’s Bruno Guimaraes, Liverpool’s Fabinho and West Ham’s Lucas Paqueta.
A talented selection of forwards sees the likes of Manchester United’s Anthony and Tottenham’s Richarlison join Paris St-Germain star Neymar in Qatar.
Firmino has not played for Brazil since last year’s defeat by Argentina in the Copa America final, with his form this season not enough to force his way back in, with Real Madrid duo Rodrygo and Vinicius Jr, plus Barcelona’s Raphinha, also preferred.
Brazil have won five World Cup titles, with their most recent victory in 2002, but lost 2-1 to Belgium in the quarter-finals in 2018.
Brazil squad
Goalkeepers: Alisson (Liverpool), Ederson (Manchester City), Weverton (Palmeiras)
Defenders: Dani Alves (UNAM), Danilo (Juventus), Alex Sandro (Juventus), Alex Telles (Sevilla), Bremer (Juventus), Eder Militao (Real Madrid), Marquinhos (PSG), Thiago Silva (Chelsea)
Midfielders: Casemiro (Manchester United), Everton Ribeiro (Flamengo), Bruno Guimaraes (Newcastle), Fabinho (Liverpool), Fred (Manchester United), Lucas Paqueta (West Ham)
Forwards: Antony (Manchester United), Gabriel Jesus (Arsenal), Gabriel Martinelli (Arsenal), Neymar (PSG), Pedro (Flamengo), Raphinha (Barcelona), Rodrygo (Real Madrid), Richarlison (Tottenham Hotspur), Vinicius Jr (Real Madrid).
