The Nationals optioned Ribalta to Triple-A Rochester on Tuesday.
Ribalta appeared in two games and logged a 13.50 ERA across two innings during his first MLB stint. The 26-year-old will yield his spot on the 26-man roster to Robert Garcia, who returns from the bereavement list Tuesday. Ribalta has a 3.62 ERA and 35 strikeouts in 27.1 innings for Triple-A Rochester this season.