Trainers look on their 2-year-olds the way demanding parents look on their children. They invest in the youngsters all their hopes and dreams for the future. So even before a thoroughbred has had first serious workout of his life, the trainer will be scrutinizing his every move for signs of potential greatness.

John Veitch saw those signs las winter in Miami. One morning he was escorting a visitor through his barn at Hialeah and passed near a colt who made his eyes brighten - as if he could envision the day when he would be shooting for the 2-year-old championship. That day will come Saturday in the Laurel Futurity.

"This colt is a natural," Veitch exclaimed. "He's got that spirit. When he's galloping and another horse comes toward him, he'll prick his ears and dig in. He's a toughie. His name is Rivalero."

Veitch continued to stroll through the barn and passed a colt named Tim The Tiger without comment - as a parent might want to forget the existence of a wayward son who had tarnished the family name. Tim The Tiger had shown such a lack of aptitude that he was sure to be an embarassment to Calumet Farm.

He was held in such low esteem that when Rivalero, Alydar and the rest of the Calumet horses were flown from Miami to New York, Tim The Tiger did not merit a spot on the plane. He was loaded into a van with a stable pony and one other nondescript racehorse and driven unceremoniously from Hialeah to Belmont Park.

That was the last indignity he would ever suffer. For while the precocious Rivalero was showing himself to be a racehorse of only average ability, Tim The Tiger proved to be the guttiest, most competitive thoroughbred of his generation. He could earn the title as the champion of his age group if he defeats General Assembly and Spectacular Bid at Laurel on Saturday.

"I've never in my life had a horse who surprised me so much," Veitch said. "Before our 2-year-olds have ever worked, we grade them all on the basis of the way they move, the way they gallop, how intelligent they are. Of the six colts we had at Hialeah, Tim The Tiger was No. 6. He was a dummy. He was a big and ungainly ugly duckling and when he went to the track he'd stumble around and his legs would go in four different directions.

"I hoped maybe by the time he was a 4-year-old he'd be straightened out. But I could just train him so much and so I decided to run him and give him a taste of combat."

That, as things turned out, was just what Tim The Tiger had been waiting for. In his debt he hooked up with a well-regarded rival named Fuzzbuster, battled him doggedly for every step of the race and won in a photo finish. Jockey Jeffrey Fell told Veitch after the race, "He wouldn't have let Fuzzbuster get by him if they ran around the track four times."

Tim The Tiger had the same zest for competition, the same indomitable spirit that Affirmed displayed in this year's Triple Crown races, beating Alydar in their head-to-head duels and making life miserable for Veitch. It was poetic justice that Calumet now had such a horse. After his maiden victory, Tim The Tiger won four straight stakes, the last of them all a stirring triumph over the ballyhooed General Assembly in the Cowdin Stakes.

Tim The Tiger's winning streak ended abruptly in the Champagne Stakes at Belmont three weeks ago. Spectacularly Bid and General Assembly both trounced him. Veitch went back to his barn expecting to see that Tim The Tiger had hurt himself, or was running a fever. But nothing was wrong. So Veitch decided to give the colt one more chance on Saturday.

Tim The Tiger's chances appear bleak. Spectacular Bid probably possesses more raw ability than he does, and horses rarely revert to their old form after a sound defeat such as he suffered in the Champagne. Veitch knows these drawbacks, but he also knows that it can be a mistake to underestimate Tim the Tiger.