The showdown won’t happen tomorrow at the Belmont Stakes. Mine That Bird, winner of the Kentucky Derby, will not get the chance to avenge his loss in the Preakness to Rachel Alexandra because the filly's owner has decided to rest her out of concern for her long-term health.

Despite the absence of Rachel Alexandra, there are a number of compelling storylines in this year’s Belmont. First is Calvin Borel, the jockey who steered Mine That Bird to victory in the Derby (video) only to switch horses but repeat his success with Rachel Alexandra in the Preakness (video). Borel is back on top Mine That Bird and looking to complete a personal Triple Crown. He is certainly confident, guaranteeing victory, but there are a number of challengers in his way.

Charitable Man, a horse that has never lost on dirt, is rested and ready to go. Dunkirk, a horse trained by Todd Pletcher, was an early Derby favorite who stumbled out of the gate in that race and looking for redemption. But perhaps the best indication of the unpredictability of horse racing is the simple fact that Mine That Bird was a 50-1 long shot when he won the Derby five weeks ago. Will another long shot emerge tomorrow? Post time is 6:27pm and the race is on ABC.