By Racinguk.com staff
The Irish Grand National hero could never get competitive on his seasonal debut and trailed in last of the seven finishers behind Outlander in the Grade One contest over three miles.
Harrington said: "Our Duke is sound, he scoped wrong. He has done it once before. They took some bloods from him [on Sunday morning] and we'll take it from there. I just don't know and I'm scratching my head. He was gone after the first fence."
Meanwhile, Jonjo O'Neill could look to the handicap route for More Of That, who trailed home sixth in the feature, with only Our Duke behind him.
O'Neill said: "He ran OK, but that is all he did do. I was really happy with him going there, he was in really good form at home.
"I was a shade disappointed, if I am honest. He is nine now and has had his problems and he is probably not the horse he used to be. We will probably have to go the handicap route now."