Toussaint was optioned to Triple-A Gwinnett on Friday.
The 23-year-old was competing for a spot in Atlanta's starting rotation but once the season resumes, he'll begin 2020 in the minors. Toussaint appeared in 24 games (one start) for the Braves last season and had a 5.62 ERA, 1.68 WHIP and 13.1 percent walk rate over 41.2 innings