By Racinguk.com staff
The eight-year-old carried all before him last season, but this campaign has not gone to plan after an impressive return in the John Durkan Memorial Chase at Punchestown in December.
He was sent off the hot favourite after that to win the Leopardstown Christmas Chase but was well beaten in seventh place, and although Harrington was hopeful he was returning to his best for the Festival, a "hairline non-displaced fracture of his pelvis" has dashed plans.
Harrington revealed in her blog for Unibet: "It is with a heavy heart I have to report that Sizing John will miss the Cheltenham Gold Cup. He cantered as normal this morning at Commonstown and during routine checks this afternoon was found to be sore behind.
"I have had our vet Mark McRedmond come and check him over. He has found a hairline non-displaced fracture of his pelvis. He will have box rest for two weeks and then be rescanned with a view of starting walking exercise.
"This is a massive blow for the Potts family and for all our team here at Commonstown."
Harrington will now rely on Our Duke, with Robbie Power, who was retained to ride Sizing John, switching back to him.
It means Noel Fehily, who partnered Our Duke in a workout this week, finds himself surplus to requirements.
William Hill responded by cutting Might Bite from 3-1 to 5-2, with Native River 9-2 from 11-2. Our Duke has shortened to 11-2.
"Might Bite is one of our worst results and we are gutted by Sizing John’s absence, he was perhaps our ace in the hole,” said William Hill spokesman Rupert Adams.
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