By Steve Ginsburg

ELMONT, NEW YORK (Reuters) - Big Brown's quest to become the first Triple Crown winner in three decades will not be affected by the stifling heat predicted for Saturday's Belmont Stakes, the colt's trainer said Thursday.

Temperatures for the highly anticipated $1 million race were expected to top the 90-degree (32 Celsius) mark.

"I can't imagine (the heat) being a factor. None whatsoever," trainer Richard Dutrow, Jr. told reporters. "Not for our horse. I don't know about the other horses."

Dutrow was supremely confident Kentucky-bred Big Brown will become the 12th Triple Crown winner despite a potentially troublesome cracked hoof and a tricky inside post draw.

The Kentucky Derby and Preakness Stakes winner jogged around the Belmont Park track early Thursday and Dutrow pronounced the three-year-old son of Boundary in excellent shape.

Despite hordes of reporters and onlookers milling around his stable this week, Big Brown appears not to have noticed the attention he has drawn.

"I'm telling you, this horse is so cool," said Dutrow, who will be saddling his first Belmont Stakes horse. "Every time I see this horse do something, he absolutely amazes me."

Unbeaten in five career starts, Big Brown is the overwhelming 2-5 favorite in the grueling mile-and-a-half affair. His chief rival appears to be Peter Pan Stakes winner Casino Drive, a 7-2 second choice in the field of 10.

Casino Drive has raced just twice, a 12-length triumph at Kyoto race course in February and a 5 3/4-length victory in the Grade II Peter Pan last month at Belmont Park.

"He goes to the paddock for 15 minutes every day, and there is so much press that it is good for him," said Nobutaka Tada, spokesman for Japanese owner Hidetoshi Yamamoto and trainer Kazuo Fujisawa.

"He is very fit and he will be ready for the Belmont Stakes."

Among those also running Saturday will be Preakness runner-up Macho Again and third-place finisher Icabad Crane, and Florida-bred Denis of Cork, who ran third in the Derby.

But all eyes will undoubtedly be on Big Brown, who will attempt to avoid becoming the 11th horse since 1979 to lose a shot at Triple Crown immortality at the Belmont.

(editing by Justin Palmer)