A fractured sesamoid suffered by My Brent's Diamond in a March 1 workout at Fair Grounds will force the retirement of the six-time stakes winner. My Brent's Diamond fractured her left-front sesamoid while working ahead of the Victoria Lass Handicap for trainer Jerry Quinn.Michael R. Meeks' Louisiana-bred My Brent's Diamond (My Mike--Brent's Diamond, by Diamond Shoal) defeated Hallowed Dreams in each of her last two starts, the Louisiana Champions Day Sprint versus males in December and the $72,750 Pan Zareta Handicap last month. In her lone attempt at a graded stakes, she finished fourth in the Thoroughbred Club of America Stakes (gr. III) at Keeneland last October. The 5-year-old mare won nine of 23 career races for earnings of $397,761.