Ria Antonia will be the first filly to run in the Preakness Stakes since 2009 when Rachel Alexandra won the race.

Calvin Borel, who guided Rachel Alexandra to victory, will ride the Tom Amoss-trained filly who finished sixth in the Kentucky Oaks.

Amoss said the idea to run Ria Antonia against the colts was the owners' choice.

She only joined his stable three days after the Oaks when the owners decided to transfer her from Hall of Fame trainer Bob Baffert.

"I don't know what happened in the Oaks, but I like the way she looks now," Amoss said.

"We have a healthy, sound horse and we are ready to roll the dice."

Amoss says he sees the Preakness as a race between Kentucky Derby winner California Chrome against everyone else.

He said if California Chrome ran his race as he did in the Derby he would win, but if not, it would open up opportunities for the others.

Ria Antonia will have another work-out at Churchill Downs in Kentucky before travelling to Baltimore on Wednesday.

California Chrome galloped at Churchill Downs on Monday before being flown to Baltimore.

"Everything is perfect," Alan Sherman, assistant to his father and trainer Art Sherman, said.

Also on the same flight were Preakness contenders Ride On Curlin, who finished seventh in the Derby with Borel on board, General a Rod, who was 11th in the Derby and Pablo Del Monte, who didn't run after drawing barrier 20.

Saturday's Preakness Stakes is the second leg of the US Triple Crown.