But he's not so sure about the Preakness.
"It is going to take an awful lot of luck to win this one," Miller said. "With this horse's enormous stride and the large sweeping turns [at the New York track], it's the Belmont that is our cup of tea."
The 71-year-old trainer, and his wife, Martha, arrived at Pimlico Race Course for the first time yesterday afternoon and immediately checked in on Sea Hero.
Miller added that he is "cautiously optimistic" about the horse's chances Saturday, mainly because Sea Hero has recovered so well from his winning race in the Kentucky Derby.
The horse had a limbering up "breeze" at Belmont Park last Saturday (going a half mile in 50 seconds) and will sharpen his speed this morning at Pimlico with a three-eighths of a mile workout "in probably 35 or 36 [seconds]," Miller said. Jockey Jerry Bailey is flying down from New York for the workout.
But, Miller said, "There are two deterrents [in the Preakness]. First, this track has sharp turns and is conducive to speed horses. Secondly, the race is a sixteenth of a mile shorter [than the Derby]."
On top of that, Sea Hero ran on Lasix in the Kentucky race. But Miller will not be allowed to use the medication in the Preakness because Sea Hero is not a confirmed bleeder. Miller said he didn't think it will affect the horse's performance.
Not winning the Preakness but pulling off a Derby-Belmont double would not be a Triple Crown precedent. Starting with Zev in 1923, nine horses have accomplished that feat. They also include Twenty Grand (1931), Johnstown (1939), Shut Out (1942), Middleground (1950), Needles (1956), Chateaugay (1963), Riva Ridge (1972) and Bold Forbes (1976).
Historically, it takes a speed horse or a horse with so-called "tactical speed" (ability to rate and lay close to the pace) to win the Preakness, although closers such as Pleasant Colony (1981) and Pine Bluff (1992) occasionally rally in time.
In the Derby, Sea Hero came from 12th place in the early going and then shot to the front in the stretch when a hole opened up on the rail.
For a closer such as Sea Hero to win the Preakness, he needs a fast pace to tire out the front-runners.
"What really appeals to Mr. [Paul] Mellon [the horse's owner] and I is that they run the first quarter in 22 [seconds] and the half mile in 44 [seconds]," Miller said. "That's what we want."
There are plenty of early speed horses in the race, such as Koluctoo Jimmy Al, Cherokee Run, Personal Hope and El Bakan. But it's doubtful that jockeys such as Pat Day on Cherokee Run or Chris McCarron on Koluctoo Jimmy Al would set those kind of suicide early fractions.
A lot will depend on the outcome of the post position draw at Pimlico this morning when the 11 horses are officially entered.
"We just have to get through this one. It's a question mark," Miller said. "We've already won the race [the Derby] I wanted to win."
Miller said he and Mellon are still in a state of euphoria over the Derby victory.
"It gave Mr. Mellon a second lease on life. Now, he's done it all [in horse racing] and I'm glad it came during my tenure of training for him."
Miller said he has been somewhat surprised by the outpouring of affection for both he and Mellon after the Derby.
"My wife has gotten about 300 letters and wires of congratulations and about 150 phone calls and more roses than we got at the Derby," he said.
"When I got home [in Versailles, Ky.] about 9:15 that night after the race, there were placards, balloons and signs all over the front of the house. Within a half hour it was filled with people. I didn't get to bed until 1:15 a.m. and then I was so wound up I couldn't get to sleep."
The next morning, at local church services, Miller and his wife received a standing ovation when they entered.
"It couldn't happen to a nicer guy," said Bruce Levine, trainer of Koluctoo Jimmy Al, who is stabled next to Sea Hero. "Mr. Miller is all class. He's the only trainer I refer to as 'Mister.' "