Aidan Coleman will be out of action until October having fractured his arm in a fall at Southwell on July 30.
Coleman was riding Dieg Man for Neil Mulholland in a handicap chase when falling at the second-last.
Writing on his website, www.aidan-coleman.com, he said: “Unfortunately, I fractured my humerus at Southwell last week after a fall.
“I’ve had plenty of contact with BHA doctor Jerry Hill and my specialist Geoff Graham, who have both been amazing, and after my scan they have told me to expect a 10- to 12-week break before I can go back racing.
“It’s obviously not ideal with the season starting off so well with some good early momentum following the coronavirus lockdown, but injuries are part of the job and every jockey has been there before.
“I’m looking forward to getting to Oaksey House in Lambourn as soon as possible to start my rehabilitation and I’m then looking forward to returning in October.”