Young Sydney jockey Andrew Adkins will miss the holiday racing period after being diagnosed with pericarditis, inflammation of the heart.

Racing NSW said on Friday, Adkins would be sidelined for at least the next two weeks.

Sydney's champion apprentice for 2016/17, Adkins rode his first Group One winner earlier this year aboard Daysee Doom in the Coolmore Classic.

Daysee Doom is trained by Adkins' former boss, Ron Quinton, who has nurtured the early careers of several of Sydney's leading riders, most notably Hugh Bowman.