Sean Williams


Racing is a family affair for Sean Williams. He’s been on the racetrack as long as he can remember with his parents and trained with his brother in the past. Williams first laid eyes on a racetrack at Wyoming Downs and currently calls the West Coast home while managing the Del Mar, Santa Anita and Los Alamitos stable. With experience as a jockey, exercise rider and assistant to Keith Bennett, Williams was breaking yearlings when introduced to Robertino Diodoro. First employed in Phoenix, Sean recalls the 2012 Phoenix Gold Cup as his favorite moment working for Diodoro, winning with Derive.  This will mark the sixth year for Sean at Diodoro Racing Stables.  Sean and his wife, Kim, reside in California with their daughter Leighton, son Layne and their newest addition, son Lukas.

Kent Knudsen 

An Idaho native, Kent Knudson gravitated to horse racing early in life, growing up around the track with his father, a trainer. After a brief stint in pursuit of a law degree, Kent his calling and returned to racing.

With previous experience under Doug Oliver and Dan McFarlane, Knudsen joined Diodoro Racing five years ago. Today, Kent assists at Turf Paradise (AZ) and Prairie Meadows (IA). He has proven himself a valuable asset, assisting in numerous training titles and championships over the years.    Kent and his wife, Manot, enjoy spending time off the track with their two sons, Kayden and Blake.

Rob Atras

A fellow Canadian, Rob Atras is the newest assistant trainer in the Diodoro Racing Stable. Rob has been involved with racing from a very young age when his mother introduced him to the horses she owned. Training seemed a natural fit for the Winnipeg native; while his first job came at home (Assiniboia Downs) with trainer Jack Robertson, his travels ranged from winters at Palm Meadows and Gulfstream with trainer Rebecca Maker to the cold of Edmonton and Northlands Park. After beginning work for Robertino in 2013, it didn’t take long for the two to achieve success in the Canadian Derby.  This victory is the one Rob counts as his most memorable since working for Diodoro Racing and the victor, Edison, is by far his barn favorite.  “He’s a character, and winning the Canadian Derby with him after working with him for a while was great.”  Rob currently manages the runners at Oaklawn Park andWoodbine in Toronto.