Keller represented Bolivia at the International Racquetball Federation (IRF) World Junior Championships in each of the last six years of eligibility.

[3] At the 2007 World Junior Championships in Cochabamba, Bolivia, Keller was runner-up in the U14 Singles to the USA's Marco Rojas, losing the final, 6–15, 15–8, 11–2.

[9] 2011 was Keller's last year of juniors, and he won the U18 Singles at the 2011 World Junior Championships in Santo Domingo, Dominican Republic, by beating Daniel de la Rosa of Mexico in the final, 15–9, 15–5, after defeating the De La Rosa's team-mate Jaime Martell, 15–11, 15–6, in the semi-finals, and Jose Diaz of the US in the quarterfinals, 10–15, 15–11, 11–9.

There he reached the final with wins over Colombians Juan Herrera in the quarterfinals, 15–13, 15–7, and Francisco Gomez, 15–2, 15–3, in the semi-finals, but lost to team-mate Ricardo Monroy, 15–11, 15–8.

[12] At the 2010 Pan American Racquetball Championships, he lost in the Round of 16 to Costa Rica's Ivan Villegas, 15–11, 15–3, in Men's Singles[13] but reached the podium with Ricardo Monroy in Men's Doubles, as they beat Argentines David Maggi and Shai Manzuri, 15–8, 5–15, 11–5, but then lost to Mexicans Ruben Estrada and Alejandro Landa, 15–14, 15–7.

[17] Keller played at the 2011 Pan American Racquetball Championships in Managua, Nicaragua, reaching the quarterfinals in Men's Singles, where he lost to Daniel de la Rosa of Mexico, 15–2, 15–8.

[19] Keller played at the 2011 Pan American Games in Guadalajara, Mexico, where he lost in the quarterfinals of Men's Singles to the USA's Rocky Carson, 15–11, 15–0.

[23] In the Men's Team event, Bolivia came fourth after losing in the semi-finals to the United States and then dropping the third-place match to Mexico.

[25] He beat Marco Rojas in the final, 15–4, 15–12, after defeating Alejandro Herrera, 15–14, 15–8, in the semi-finals, Jose Diaz in the quarterfinals, 13–15, 15–14, 11–8, and David Horn in the Round of 16, 9–15, 15–10, 11–6.

[26] Keller was a bronze medalist at the 2013 Pan American Championships, as he reached the semi-finals with a forfeit win over Daniel Maggi of Argentina in the quarterfinals.

He defeated Costa Rican Felipe Camacho in the Round of 16, 15–10, 14–15, 11–7, and Mexican Álvaro Beltrán in the quarterfinals, 15–12, 15–11, but lost to the US's Jake Bredenbeck, 15–13, 15–13, in the semi-finals.

[33] In 2016, Keller played Men's Doubles at Worlds with Kadim Carrasco, and they beat Canadians Mike Green and Tim Landeryou, 6–15, 15–2, 11–8, in the quarterfinals, which put them in the semi-finals against the US's Jake Bredenbeck and Jose Diaz, losing 15–14, 8–15, 11–8.

Keller won Men's Singles at the 2018 Pan American Championships in Temuco, Chile, where he beat David Horn of the US in the final, 15–12, 5–15, 11–7.

[38] En route to the final, Keller defeated Edwin Galicia of Guatemala, 15–7, 7–15, 11–5, in the Round of 16, Cuban Maikel Mollet, 15–7, 15–7, in the quarterfinals, and Mexican Rodrigo Montoya, 15–6, 2–15, 11–4, in the semi-finals.

He reached the final by beating Canadian Coby Iwaasa in the Round of 16, 15–10, 15–9, David Horn of the US, 15–10, 15–12, in the quarterfinals, and Mexico's Álvaro Beltrán in the semi-finals, 15–13, 15–8.

[42] In Denver, Keller beat Samuel Murray, 15–6, 15–4, in the Round of 16, Mario Mercado in the quarterfinals, 15–13, 14–15, 11–6, before losing to fellow countryman Conrrado Moscoso in the semi-finals, 15–10, 15–14.