Bradstock also provided a positive update on Step Back, who rounded off last season with victory in the bet365 Gold Cup at Sandown.
"He's really good and I think we're learning to deal with the tying up (muscle cramp) problems he's had in the past," Bradstock added. "The Grand National is the long-term target and we'll keep our options open in terms of where we start off. Whether we go for the Hennessy (Ladbrokes Trophy) or the Becher Chase, we'll see. It will slightly depend on the ground, so we'll see what happens."