US champions Princess Of Sylma and Will Take Charge have been retired to begin their breeding careers.

Will Take Charge, last year's US 3-year-old male champion and Horse of the Year finalist, has been retired to take up stud duty in 2015 at Three Chimneys Farm in Kentucky.

The horse was retired due to a mild suspensory strain.

"Will Take Charge is a serious racehorse and is an even more important stallion prospect," said Doug Cauthen, vice chairman of Three Chimneys.

"His body of work on the racetrack is remarkable and unique, and his magnificent pedigree anchors a physical presence that will impress any breeder that sees him. To me, he's as good as it can get."

By Unbridled's Song out of Kentucky Broodmare of the Year Take Charge Lady, Will Take Charge won seven of 21 starts and earned $3,924,648 for trainr D. Wayne Lukas.

In his championship season he had 11 starts at eight different tracks, winning the Smarty Jones Stakes, Rebel Stakes, Travers Stakes and Pennsylvania Derby and Clark Handicap and finished second, beaten just a nose, in the Breeders' Cup Classic.

This year had six starts, winning or hitting the board in five of them.

"Will Take Charge's retirement is particularly disappointing as we were primed, as an older horse, to win the Breeders Cup Classic this year which we lost by a whisker last year," Lukas said.

“This horse has done what few other horses can do any more. He is a true champion who ran to his blue-blooded pedigree.

Four-time G1 winner Princess of Sylmar, a winner of more than $2 million, was diagnosed with a case of thumps after she finished an uncharacteristic fifth in her last start in the G1 Personal Ensign Stakes at Saratoga on August 22.

After the Personal Ensign there were plans to continue racing Princess of Sylmar, but she didn't progress quickly enough according to trainer Todd Pletcher.

"Preparing her for her next race was taking longer than I expected," Pletcher said.

"Because she will miss this year's running of the Beldame and the Spinster we decided that timing is such that we decided to retire her."

Princess of Sylmar earned $2,017,220 from nine wins and three seconds in 15 starts including victories in the G1 Kentucky Oaks, G1 Coaching Club American Oaks, G1 Alabama Stakes and G1 Beldame Invitational.