Assad will start Thursday's game in St. Louis, Meghan Montemurro of the Chicago Tribune reports.
Shota Imanaga had been listed as the starter for Thursday's series finale, but he and the other Cubs starters will be pushed back in order to bake in some extra rest. Assad went three shutout innings out of the bullpen in his last appearance Saturday in Pittsburgh, so he'll be taking the ball on four days' rest. The righty has not made a start in nearly three weeks, so he will not have a full workload at his disposal.