ARCADIA, Calif. – An unspecified setback has knocked the exciting 3-year-old Honor A. P. out of the Grade 3 Sham Stakes on Saturday at Santa Anita. John Shirreffs trains Honor A. P., expected to start as the favorite in the one-mile Sham based on his dazzling maiden victory during the autumn meet. However, after training on Tuesday at Santa Anita, Honor A. P. showed signs of something being amiss. “He came off the track and after he cooled out, he was off,” Shirreffs said early Wednesday morning. “We did X-rays, and the X-rays were okay. We’ll just have to wait and see.” Shirreffs did not speculate. “We’re hoping it may be something minor. He won’t be able to run this weekend.” Honor A.P. is widely considered one of the top Derby prospects in California. Owned by Lee Searing’s CRK Stable, the son of Honor Code finished second in his career debut in a summer sprint at Del Mar, then stretched to a mile and won by more than five lengths with a 91 Beyer. The Sham would have been his third career start, and the launch of his 2020 campaign. Although initial X-rays did not reveal the underlying problem, horses typically are X-rayed again a week after the issue surfaces. The second round of X-rays can reveal the specificity of the setback, or it could be something as minor as a deep foot bruise. “Right now, it’s really difficult to say other than he’s not going to run Saturday,” Shirreffs said. Honor A. P. was listed as low as 14-1 favorite to win the 2020 Kentucky Derby by William Hill. The defection of Honor A. P. from the Sham lessens the race’s appeal, although the $100,000 race is expected to attract Richard Baltas-trained maiden winner Taishan. Bob Baffert nominated four, including 87-Beyer debut sprint winner Authentic and dominating debut route winner Azul Coast. Entries for the Sham will be taken later Wednesday.