Toussaint will start Thursday's series opener at Colorado, Mark Bowman of MLB.com reports.
Manager Brian Snitker indicated earlier in the week Toussaint may rejoin the rotation in the coming days, and he'll do so Thursday against the Rockies. The right-hander has pitched well since joining the big-league club after the All-Star break with a 3.60 ERA, 1.15 WHIP and 40:15 K:BB across 40 innings.