Toussaint was optioned to Triple-A Gwinnett on Sunday.
This comes as a bit of a surprise, as the right-hander appeared to have the inside track at a rotation spot following injuries to Mike Foltynewicz (elbow) and Mike Soroka (shoulder). Toussaint posted an unsightly 8.62 ERA through six spring appearances (15.2 innings), but his 20:3 K:BB over that stretch is a better reflection of how he pitched. The young right-hander figures to join the big-league rotation at some point in 2019, though he'll head to the minors to work some kinks for the time being.