Cormorant worked an excellent five furlongs in :57 35 yesterday at Laurel. A few hours later, the strongest challenger for undefeated Seattle Slew in the May 21 Preakness Stakes was loaded onto a van for New York and an assignment Saturday at Aqueduct in the Withers Mile.

Seattle Slew is not the only 3-year-old this spring to work as soon as the shortly after 6 a.m. for his drill, posting fractions of :11 1/5, :22 3/5, :34 1/5 and :46 under a hand ride by jockey Danney Wright before galloping out three quarters of a mile in 1:11 15.

Cormorant is asked to work much faster than the Kentucky Derby winner. he recently recorded a :58 at Laurel for trainer Jimmy Simpson, prompting Dick Dutrow to proclaim: "It was the greatest I have ever seen a horse work.

"Four years ago, I saw Ron Turcotte work Secretariat at Pimlico the Sunday before the Preakness," Dutrow continued, "and he went six furlongs in 1:10. The way he was moving, I didn't thing a horse could run that fast. But I believe Cormorant's work was the best I've seen. You wouldn't believe the hold the boy had on him at the three-eights pole, and was doing it on a deep track."

Dutrow won an Eclipse Award in 1975 as the nation's leading trainer in terms of number of winners. Rarely does he go overboard in praising a thoroughbred, but more and more Maryland horsemen are beginning to believe Cormorant has a good chance against Seattle Slew.

Even Simpson said, after watching Slew win the Wood Memorial in New York, that he thought Cormorant might have beaten the favorite that day.

"It looked to me as if Seattle Slew was ripe for plucking," the trainer said. "If there ahd been a strong horse in the Wood that could have run at him in the stretch, he could have been beaten."

A viral infection, suffered three weeks before the Derby, prevented Cormorant from shipping to Louisville for the opening event in the Triple Crown series.

"If I had already been in kentucky and he had worked well, I would have tried to run him in the Stepping Stone and then the Derby," Simpson said.

Instead, the trainer kept cormorant at Laurel, giving him extra time to prepare for the Preakness' 1-3/16 miles. The Withers is his final preparation, with Ruthie's Native likely to be his main rival.

Cormorant is unbeaten thisy year, having won the Iroquois, Bay Shore and the Gotham Stakes. The son of His Majesty has lost only once in his career, in his first start as a 2-year-old, when he bolted.

A field of seven is in long-range prospect for the Preakness. J.O. Tobin, a champion in England at 2, and the best 3-year-old in California this spring, already is at Pimlico. He drilled a half-mile in :46 yesterday morning and will work a mile on Saturday.

Sanhedrin, Affiliato, Sir Sir and Counter Puncher also are being pointed for the race. Sanhedrin ran third at Churchill Downs, a neck behind runner-up Run Dusty Run and approximately two lengths behind Seattle Slew.

Pimilco officals still are awaiting word regarding the Preakness status of Run Dusty Run, but For The Moment, the third choice in the Derby, will skip the Preakness in favor of the Jersey Derby, trainer LeRoy Jolley said yesterday.