Fabián Cornelio Balbuena González signed with Club Cerro Porteno (Presidente Franco) as a teenager, spending two years with the side and helping them to win the Division intermedia, the second tier of the Paraguayan football league, in 2011. Moved to Club Rubio Nu in 2013, playing 17 times, before switching to Club Nacional Asuncion later in the year. After 42 appearances in all competitions for Nacional, signed for one of Paraguay;’s most prominent sides, Club Libertad, in 2014. Established himself as an important aspect of the team that won both the Torneo Apertura and the Torneo Clausura in his maiden season. Balbuena earned his first international cap against Mexico in 2015.

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Departed his home country and transferred to Brizilian team Corinthians in 2016, winning the Campeonato Brasileiro Serie A and the Campeonato Paulista in his first season in Sao Paulo. Nicknamed ‘El Comandante’ – the General – for his leadership on the pitch.

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The international defender joined West Ham United on a three-year contract for an undisclosed fee on 14 July 2018. Made his debut against Liverpool in a 4-0 defeat at Anfield on 12 August 2018. Sccored his first goal against Leicester City on 27 October and ended the season with 23 Premier League appearances.

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Fell out of favour with manager David Moyes and lost his place to Anglo Ogbonna. In May 2021, Baluena was told that his contract would not be renewed when it expired at the end oof the 2020/21 season.

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On 9 July 2021, he signed a four-year contract with Russian Premier League club FC Dynamo Moscow. On 10 July 2022, Balbuena suspended his contract with Dynamo Moscow for the 2022–23 season, having taken advantage of the FIFA ruling relating to the Russian invasion of Ukraine. Eight days later, he returned to Corinthians for the period of his Dynamo contract suspension, until 30 June 2023. At the end of this suspension, Balbuena returned to Dynamo in July 2023. After returning to the Moscow club, Balbuena was chosen as the team captain for the next season