NEW YORK — Casino Drive will not run in the Belmont Stakes because of an injured hoof, removing one more obstacle between Big Brown and the Triple Crown.

Casino Drive was the early second choice behind the overwhelming favorite, who is attempting to become the first Triple Crown winner in 30 years.

Racing manager Nobutaka Tada for Casino Drive's Japanese connections said the horse was fine during a three-furlong jog early Saturday, but planned to scratch the Peter Pan Stakes winner as a precaution.

Tada classified the injury as minor, but didn't want to take any chances during the grueling 1½-mile race.

"It's not serious, it's just a matter of timing," Tada said. "The horse is OK."

Casino Drive developed symptoms on Friday, and was held out of his morning gallop. He was treated with ice overnight and showed no ill effects while on the track early Saturday.

The horse will be shipped back to Japan on Tuesday, but could return later this year to run in the Breeders' Cup.

Casino Drive may have a stone bruise, which can be caused by walking on hard, rocky ground. The colt has been walked all over Belmont Park's horse paths this week, a training technique favored by the Japanese. American trainers typically gallop or jog their horses on the track in the days leading to a race.

"It's very sad," Tada said. "Many people support us. It's sad that we couldn't meet the expectations."

Tada said he wasn't sure if scratching Casino Drive would make it easy for Big Brown to become the first Triple Crown winner since Affirmed in 1978.

"I don't know (but) I'd like to see him win," he said.

Big Brown's trainer Rick Dutrow Jr. was not available for comment. The brash Dutrow had downplayed the threat of Casino Drive all week, saying there was no horse in the field talented enough to take on his talented bay colt.

Big Brown, who had an acrylic patch placed on his front left foot Friday to repair a small crack, was resting comfortably inside Barn 2 on Saturday morning. A retaining wall was set up outside the barn to keep the media and well-wishers at bay.

Denis of Cork, a distant third to Big Brown in the Kentucky Derby, was the third choice