Keenan had the opportunity to represent Spain but he chose for Argentina. He made his debut for the senior national team in the 2019 FIH Pro League. In July 2019, he was selected in the Argentina squad for the 2019 Pan American Games. They won the gold medal by defeating Canada 5-2 in the final. On 25 June 2021, he was chosen to represent Argentina at the 2020 Summer Olympics.