Triple Crown winner American Pharoah worked five furlongs in a flat 60 seconds at Santa Anita on Sunday as Bob Baffert’s star colt continues to progress toward his possible final career start in the Breeders' Cup Classic.

"He looked great," Baffert said of the work in which the son of Pioneerof the Nile ran his last half mile in 47.4.

The work under jockey Martin Garcia was the second for the colt since his upset loss to Keen Ice in the Travers Stakes at Saratoga last month.

The Travers snapped an eight-race win streak for American Pharoah and was only his second loss in 10 career starts.

The BC Classic over 10 furlongs at Keeneland on October 31 is shaping as a showdown between American Pharoah, who will enter stud at Ashford Stud at the end of his racing career, and the Spendthrift Farm-owned mare Beholder, an impressive winner of her third G1 Zenyatta Stakes at Santa Anita Park on Saturday.

Last year’s Breeders' Cup Classic winner Bayern, a stablemate of American Pharoah, and former juvenile champion Shared Beliefe are both out of the picture.

Bayern has been retired after he could finish only third to Smooth Roller in the G1 Awesome Again Stakes at Santa Anita last Saturday.

The Awesome Again is California's top Breeders' Cup trial. Bayern surrendered tamely in the straight to continue his unfortunate sequence of not having won since last year's Classic, leaving jockey Martin Garcia to report that he is simply not the same horse as last year.

Owner Kaleem Shah confirmed that the four-year-old would be retired to Kentucky’s Hill 'n' Dale Stud.

"Bayern has given my family memories of a lifetime and I am grateful for that," said Shah.

Smooth Roller, trained by Victor Garcia, is the new kid on the block and looms as the BC Classic wild card.

He did not make his debut until June and was winning for the third time in four starts as he went away to beat G1 winner Hoppertunity by more than five lengths.

“I thought we had a good shot in the race but the only way to find out is to run with the big boys and the horse ran like I expected,” Garcia said.

Also missing from the BC Classic picture is Shared Belief, who has not raced since suffering a non-displaced hip fracture in the G2 Charles Town Classic in April.

He is in training with expectations that he could return to the races at Santa Anita’s winter meeting that begins in December.

"He's jogging at the Pegasus Training and Rehabilitation Center in Washington near Seattle," said Dan Ward, assistant to his Hall of Fame trainer Jerry Hollendorfer.

"From there I believe he would return to train at Golden Gate Fields because he's been training on a synthetic surface at Pegasus and Golden Gate also has a synthetic surface.

“If all goes well, we hope to be ready for the big meet at Santa Anita."

Shared Belief was named champion 2YO male in 2013 and has 10 wins from 12 lifetime starts, including five G1 races.

He won three straight races in the G1 Malibu, G2 San Antonia Invitational and G1 Santa Anita at Santa Anita early this year after his fourth to Bayern in last year's controversial Breeders' Cup Classic.