The exciting four-year-old is unbeaten in four starts for Henderson, but he is reported off colour by the Seven Barrows handler.
Henderson said: "Unfortunately we have a small issue with We Have A Dream and he, I'm afraid, must be considered unlikely for the Triumph Hurdle."
He went on: "He didn't eat up last night, which is extremely unlike him, and we will be checking his temperature regularly."
The trainer added that he is "monitoring the situation" and that he "will try to make a definitive decision as soon as possible".
Henderson is, though, at least responsible for Apple's Shakira, the Triumph Hurdle ante-post favourite.
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