In a powertrain that includes an engine driveably connected to a load and an electric machine driveably connected to the load, a method for controlling a vehicle located on an incline against rollback includes determining a magnitude of wheel torque required to prevent the vehicle from rolling back, determining whether the electric machine has a current torque capacity that is equal to or greater than the required wheel torque, using the electric machine to produce the required wheel torque provided the current torque capacity of the electric machine is able to produce the required wheel torque, and using the engine to produce the required wheel torque provided the torque capacity of the electric machine is unable to produce the required wheel torque.