[1][2] Born in Luque, Paraguay, Romero started his career at local club Sportivo Luqueño in 1977, by 1979 Romero's consistent performances had earned him a place in the Paraguay national team that played in the FIFA World Youth Championship and was considered one of the best players of the tournament along with Diego Maradona.
In the same year, Romero played a key role in Paraguay's win in the Copa América, scoring three goals.
In 1980, he joined now defunct New York Cosmos where he played alongside such greats as the Brazilian and German World Cup winning captains of 1970 and 1974 Carlos Alberto and Franz Beckenbauer.
In 1986, he was a key player in helping the Paraguay national team return to the FIFA World Cup finals after a 28-year hiatus.
Romero returned to South America where he played out his career with Olimpia, Club Cerro Corá and Sportivo Luqueño in Paraguay and Deportes La Serena in Chile.