Triple Crown hopeful American Pharoah is set to work fast at Churchill Downs as he continues his preparation for the $1.5 million Belmont Stakes in New York on June 6.

Kentucky Derby winner American Pharaoh galloped 1 3/16 miles on the Churchill Downs main track under regular exercise rider Jorge Alvarez on Saturday, the second time the Bob Baffert-trained colt has worked since his return on May 18 after his victory in the Preakness Stakes at Pimlico.

Baffert's chief assistant Jimmy Barnes continues to be pleased with the manner in which the colt is training.

"These are just our easy days, so we're basically just keeping him happy and keeping some weight on him," Barnes said.

Baffert will return to Louisville on May 26 when he will determine when the horse will work fast.

"He hasn't decided whether he will have one or two workouts," Barnes said.

"He'll will be in on Tuesday morning and I'm sure that's when he will start deciding."

Barnes said American Pharaoh is likely ship to Belmont Park on June 2

Meanwhile the Mike De Kock-trained Mubtaahij will be ridden by Irad Ortiz for the first time in the Belmont Stakes.

De Kock forced to find an alternative jockey as French champion Christophe Soumillon is unavailable.

De Kock had a runner in the Kentucky Derby for the first time when UAE Derby winner Mubtaahij finished eighth of 18 behind American Pharoah.

"Christophe Soumillon has contractual obligations, he has to ride for the Aga Khan and won't be able to make it to the Belmont,” De Kock said.

"I think we have found a good replacement. Irad Ortiz comes highly recommended and he knows his way around Belmont."

Mubtaahij is a 12-1 shot for the Belmont with American Pharoah odds-on to become the first US Triple Crown winner since Affirmed in 1978.