In August 2015, Casco was close to a €2.5 million move to French club Olympique de Marseille. The transfer fell through when compatriot Marcelo Bielsa unexpectedly resigned as the Ligue 1 team's manager.[4]
On 9 September 2015, Casco signed a three-year contract with CA River Plate, with the Buenos Aires–based club purchasing 85% of his economic rights for $3 million.[5] He made his debut four days later in the Superclásico against arch-rivals Boca Juniors, a 1–0 home loss.[6] On 18 July 2017 he signed an extension until June 2020.[7] On 12 February 2021 he signed an extension until December 2023.[8] On 13 September 2022, he extended his contract until December 2025[9]
Absent from the national team since the 2015 tournament, Casco was a surprise inclusion for the 2019 Copa América in Brazil, with Lionel Scaloni picking him ahead of Gabriel Mercado.[12] He played one game of a third-place finish, the 1–1 group draw with Paraguay at the Mineirão.[13]
^Maverino, Silvio (12 September 2015). "Casco debuta ante Boca: ¿Cuántas veces pasó?" [Casco debuts against Boca: How many times has this happened?]. Fox Sports (in Spanish). Retrieved 16 May 2020.