Diego Calvo has international experience playing with Costa Rica in 2014 World Cup Qualifying and was on the roster for the 2014 World Cup in Brazil. He made his international debut against the U.S. in World Cup Qualifying in Colorado on March 22, 2013 and scored his first goal for Costa Rica in the next match against Jamaica. He has one goal in 10 international appearances to his credit. Additionally, he was a fixture for Costa Rica at the 2011 FIFA U-20 World Cup in Colombia.
On the club level, he started his pro career in 2010 with Alajuelense in Costa Rica, reaching CONCACAF Champions League in 2011, 2012 and in his second stint with the club in 2015. He also played during his career for Saprissa and Perez Zeledon in Costa Rica, Valerenga in Norway and IFK Goteborg in Sweden.