American Pharoah's bid to become the first horse since Affirmed in 1978 to land the US Triple Crown received a boost on Monday as two opponents withdrew from Saturday's Belmont Stakes.
Carpe Diem and The Truth Or Else both pulled out with fitness problems from the 147th edition of the "Test of the Champion" for three-year-olds, leaving just eight still standing.
Carpe Diem, who is owned by WinStar Farm, finished 10th in the Kentucky Derby and won the Blue Grass Stakes.
"We have decided not to run Carpe Diem in the Belmont. Too good a horse to run at 90%," WinStar's spokesman Elliott Walden said.
The Truth Or Else is trained and co-owned by Ken McPeek. The colt was to have been ridden by jockey Edgar Prado.
"The Truth Or Else is not being entered into Belmont. Filling in ankle. Minor but everything happens for a reason," McPeek tweeted.
The Bob Baffert-trained American Pharoah ridden by Victor Espinoza won the Kentucky Derby and the Preakness Stakes in impressive style to leave him on the brink of an achievement that has proved elusive since Affirmed's glory days.
Pharoah is the 14th horse since Affirmed to win the first two legs of the coveted treble.
Baffert has saddled four of those horses, including Silver Charm in 1997, Real Quiet in 1998 and War Emblem in 2002.
