The Union has signed Josue Martinez from Club Deportivo Saprissa.
The forward will be available upon receipt of his P-1Visa and International Transfer Certificate.
Terms were not disclosed.
Raised within Saprissa's youth system, Martinez made an immediate impact by scoring his first goal during his professional debut against Puntaneras F.C. in November 2009.
He has 18 goals in 43 appearances with the Monstruo Morado.
In 2010, Martinez and Deportivo Saprissa conquered the Costa Rican First Division Clausura title after the young forward opened the scoring against Asociación Deportiva San Carlos.
Later that season, an 87th minute-goal by Martinez against the Seattle Sounders fueled Saprissa to the CONCACAF Champions League quarterfinals.
Considered one of Costa Rica's rising stars, Martinez made his national team debut in a 1-0 victory over Venezuela in June 2009. The striker has scored two goals in 11 caps with La Sele, notching his first international tally as an international against El Salvador in October 2010.
Martinez's second international goal came in a 2-0 victory over Bolivia at the 2011 Copa America on July 7.