Verrett joined the Nationals on a minor-league deal in early February.
Verrett owns a 4.62 ERA in 150 career major-league innings, the last of which came in 2017. He spent 2018 with the NC Dinos in Korea, struggling to a 5.28 ERA, before returning stateside and getting stuck in the upper minors. His 4.74 ERA in 19 starts for Triple-A Tacoma last season hardly suggests the 31-year-old is about to make a significant impact at the major-league level.