Steve Warner, the co-breeder of 2006 champion sprinter Thor's Echo, died April 25 after a bout with cancer.
Helen of Troy, dam of champion Thor's Echo, was euthanized June 30 because of complications from laminitis.
Leading sprinter Unbridled Sidney bids for a repeat in the $250,000 Distaff Turf Sprint Championship at Calder Race Course on Saturday.
Groom Dancer, a Kentucky-bred who developed into a French group I winner and a successful international stallion, died at Cheveley Park Stud near Newmarket, England.
Stalwart, a grade I winner who sired 55 stakes winners, died March 31.