[4] Casas was subsequently promoted to the senior national team in 2017,[4] though he was unable to compete for a spot at that year's World Championships due to injury.

[5] In 2018, Casas qualified for the World Taekwondo Grand Slam by winning a silver medal at the first Open Qualification Tournament in April.

[4] That summer, he won a bronze medal at the Central American and Caribbean Games, losing in the semifinals to eventual gold medalist Bernardo Pié.

[7] At the 2019 World Championships, Casas defeated Michele Ceccaroni of San Marino in the round of 64 before falling to Lee Dae-hoon.

[8] He qualified by defeating José Rubén Nava [es] at the national selection tournament in Mexico City earlier that year.