After being in the youth ranks for eleven years, Alanís made his debut for Argentine Primera División side Belgrano in October 2014 against Banfield; coming on late in a 2–2 draw.[1][3][4] In his first three seasons with the club, Alanís made sixteen appearances in all competitions.[1] After ten further appearances in his fourth season, 2016–17, he failed to play during 2017–18.[1] On 16 January 2018, Alanís joined Arsenal de Sarandí on loan.[5][6] He scored his first career goal for Arsenal against Patronato in April 2018.[1]
Alanís agreed to sign for Godoy Cruz on 11 June, following the relegation of Belgrano to Primera B Nacional.[7][8] In 2021, he was out on loan at Sarmiento and in January 2022, he was once again sent out on loan, this time to Defensa y Justicia until the end of 2022 with a purchase option.[9]