Lonnis made his debut in the
Costa Rica Premier Division for
Cartaginés on 22 July 1990 against
Herediano and also played for
Carmelita. He however played the majority of his career for
Deportivo Saprissa, where he reached local stardom, becoming one of the most emblematic figures for the fans, either as Saprissa's or
Costa Rica's national squad goalkeeper. He was the captain for Saprissa during several seasons, where he won four national championships, as well as two
CONCACAF Champions Cup in 1993 and 1995. He totalled 362 games for the club. ==International career==