Callum Shepherd has suffered a major blow after being replaced by Rab Havlin to contest Ambiente Friendly in next month's Derby at Epsom.
Shepherd rode the James Fanshawe colt in both starts this year and finished fourth in the Listed Feilden Stakes at Newmarket before winning the Lingfield Derby Trial this month.
Ambiente Friendly, owned by the Gredley family, is 4/1 with Sky Bet for the Classic on June 1.
Havlin, 50, will be making his third Derby ride, partnering with a 3-year-old in the race for the first time.
Speaking to Racing Post, Tim Gredley said: “This is a big decision but we wanted to have more experience on the day.
Shepherd steered Ambiente Friendly to victory in the Derby Trial at Lingfield.
“Dad (Bill Gredley) and I have spoken to Callum and he has not been left out. He has ridden us many winners, but we thought Rab Havlin had more experience for big events like the Derby, which would be a big day. We every.
“Rab has ridden a winner for us and not long ago won the Group 1 Lockinge Stakes at Audience, which was a tremendous race to win.
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Trainer William Knight remains loyal to Checkandchallenge regular rider Callum Shepherd and both will be looking for a first Group 1 win in Sunday's Prix d'Ispahan.
“I think Rab went into James Fanshawe’s house this morning and sat on the horse for the first time. We’re very much looking forward to the race.”
There was more positive news for Shepherd on Tuesday when trainer William Knight said he would stick to his jockey for Sunday's Group 1 ride in the Checkandchallenge in the Prix d'Ispahan at ParisLongchamp, live on Sky Sports Racing.