The 34-year-old striker is Brazil's all-time top goalscorer with 79 and will appear at his fourth World Cup after Monday's (Tuesday AEST) announcement.
But he has struggled to return to top fitness since he tore his left ACL in October 2023. He's played eight matches for Santos this year with four goals and two assists.
"We evaluated Neymar throughout the year and noticed that ​recently he has been playing consistently ... and he has improved his fitness. He will be an important player in this World Cup," Brazil coach Carlo Ancelotti said at a press conference in Rio de Janeiro.
The Italian added he preferred experienced players for some spots in his squad, including Neymar.
"He can still improve his fitness until the first match of the World Cup," Ancelotti said.
"He has experience in this kind of competition, the love of our group, he can create a better environment in this group.
"Some of the players who were with us this year won't be happy with this list. I'm sorry, and I want to thank everyone who was with us."
Shortly before Ancelotti's squad was announced, Neymar changed his Instagram bio in a revealing way; he had only Santos as a reference of where he is currently playing and added Brazil to it.
Brazil's 26-man squad also features their main players in recent years, Vinicius Junior and Raphinha.
Ancelotti took over in May 2025 but had not summoned Neymar until Monday.
The 66-year-old extended his contract with the Brazilian Football Confederation last week to the 2030 World Cup, but has had a troubled spell in Brazil so far with many injured players out of his World Cup squad; strikers Rodrygo and Estevao are the ones he will miss the most in North America.
Brazil open their campaign against Morocco in New Jersey on June 13, followed by games against Haiti and Scotland in Group C.
BRAZIL WORLD CUP SQUAD:
* Goalkeepers: Alisson (Liverpool), Ederson (Fenerbahce), Weverton (Gremio)
* Defenders: Alex Sandro, Danilo, Leo Pereira (Flamengo), Bremer (Juventus), Ibanez (Al-Ahli), Wesley (Roma), Marquinhos (Paris Saint-Germain), Gabriel Magalhaes (Arsenal), Douglas Santos (Zenit St. Petersburg)
* Midfielders: Bruno Guimaraes (Newcastle United), Casemiro (Manchester United), Danilo Santos (Botafogo), Fabinho (Al-Ittihad), Lucas Paqueta (Flamengo)
* Forwards: Endrick (Lyon), Gabriel Martinelli (Arsenal), Igor Thiago (Brentford), Matheus Cunha (Manchester United), Raphinha (Barcelona), Vinicius Junior (Real Madrid), Luiz Henrique (Zenit St. Petersburg), Neymar (Santos), Rayan (Bournemouth).
With Reuters.
14°C