LEXINGTON, Ky. — Preakness winner Rachel Alexandra will not run in the Belmont Stakes, opening the way for jockey Calvin Borel to return to Kentucky Derby winner Mine That Bird in his quest for a personal Triple Crown.

Jess Jackson, Rachel Alexandra's co-owner, said Friday the spectacular filly "deserves a well-earned vacation."

Rachel Alexandra, the first filly to win the Preakness in 85 years, had been set to work out Monday at Churchill Downs in Louisville, and no announcement was expected until after that. But Jackson explained she simply needed a rest after running — and winning — four graded stakes races since March 14, including a dominating victory in the Kentucky Oaks.

"We know the media and many fans would have liked to see her run in the Belmont Stakes — we feel the same," Jackson said in a statement. "But all of us sincerely interested in the horse must agree that we only want to see her run when it is best for her. While she is in great shape, having strong works, and recovering well from her amazing performances, we feel Rachel deserves a well-earned vacation."

Borel was the jockey aboard for both Mine That Bird in the Derby and Rachel Alexandra in the Preakness and Oaks. He was set to ride her again in the Belmont, but Mine That Bird's trainer Chip Woolley had said he was prepared to wait — even into next week — if there was a chance Borel could become available again.

"We hate she's not going to be in there for horse racing, but at the same time it's maybe better for me," Woolley said Friday in a phone interview. "It was a very strange year where you had two great horses and the same guy riding both of them."

Borel, who was riding in nine races on Friday's card at Churchill Downs, was already planning to be aboard Mine That Bird on Monday at the Louisville track for the colt's final workout before shipping to New York for the Belmont.

"We're gonna get the job done," Borel said during a news conference at Churchill Downs.

He said Mine That Bird "worked really good the other morning. I was very happy with his work. I worked him real easy and he was bouncin'. He was a happy camper. That's all you want."

The jockey said he thinks Jackson made the right call with Rachel Alexandra.

"I think Mr. Jackson is all about the horse, not the races," he said. "It's not the money. It's his horse."

There was no immediate indication from Jackson on when or where Rachel Alexandra might race next, but he has said he would consider running her in the Mother Goose Stakes for fillies June 27 at Belmont Park.