Grondona joined the Jaguares, Argentina's professional team in Super Rugby. On 21 November 2019, he was named in the Jaguares squad for the 2020 Super Rugby season.[1] Grondona made his debut on 7 March 2020 against the Sharks.[2][3] His time with the Jaguares was cut short due to the global disruptions caused by the COVID-19 pandemic.
In November 2021, Grondona signed with Exeter Chiefs as an injury replacement for Jacques Vermeulen.[6] He quickly extended his contract with the Chiefs in March 2022 and became a key player for the team.[7]
Santiago Grondona joined Bristol Bears in 2023.[12] Despite being sidelined due to a knee injury sustained on international duty, Grondona extended his contract with the club on 3 April 2024.[13] Although he has yet to make an appearance for Bristol, Grondona made an immediate impact by scoring two tries on his debut.[14] His brother Benjamín Grondona also plays for Bristol.[15]
International career
Grondona made his debut for the Argentina national rugby team in November 2020 during a historic victory against the All Blacks. This match marked Argentina's first-ever win over New Zealand.
In August 2023, Grondona suffered another ACL injury in a match against Spain, ruling him out of the 2023 Rugby World Cup.[16]