Umana featured in two of the side's three Group D games as Costa Rica finished top thanks to seven points from a possible nine.
Next up is Greece in the knockout stages as Costa Rica seeks to make it into the quarter-finals of a FIFA World Cup for the first time.
Costa Rica's previous best effort came in 1990 when it was beaten by Czechoslovakia in the last 16, but Umana says his team-mates are focused on extending their time in Brazil.
"It is true that it is one of the strange things being away from our country, family and loved ones," he told Al Dia.
"But right now we are focused on reaching as far as possible, hopefully to July 13 when the World Cup ends.
"This team is mentally prepared to make history and we want to continue to do so in the World Cup. We are all united in a common goal."
Victory for Costa Rica would see it take on Netherlands or Mexico in the quarter-finals.