The colt has not trained since winning the Preakness Stakes last Saturday to add the second leg of the Triple Crown to his win at the Kentucky Derby.
Earlier on Wednesday, he was given his first run at Belmont, jogging around the 1-1/2 mile dirt track under the guidance of exercise rider Hector Ramos.
"We took him to the track and jogged him once around, and he looked absolutely super," said Jack Sisterson, assistant to trainer Doug O'Neill.
"The way he looked was everything and more I'd want to see in him. Energy level was high, got over the ground well, ate up everything last night."
Sisterson said I'll Have Another, who is bidding to become the first horse since Affirmed in 1978 to win the Triple Crown, would have another jog on Thursday and possibly gallop for the first time on Friday.
The final field for the $1 million race on June 9 in New York will not be decided until a few days before the jump but the connections of I'll Have Another's chief rivals, Union Rags and Dullahan, are growing with confidence.
Both horses were beaten by I'll Have Another in the Kentucky Derby but are fresh after skipping the Preakness to concentrate on the final leg.
"I wouldn't be going in (the Belmont) if I didn't think he could beat I'll Have Another," said Michael Matz, trainer of Union Rags. "He's a big horse, and once he gets into a nice rhythm ... that's why we went with (jockey) John Velazquez. He knows New York."
With Bodemeister, who finished runner-up in each of the first two legs, opting out of the Belmont Stakes, Dullahan, who finished third in the Derby, is looming as the big danger to spoil I'll Have Another's bid.
"I think we owe it to the past Triple Crown winners to make (I'll Have Another) earn it," said Dullahan's trainer Dale Romans.
"If he's a super horse, like Seattle Slew, Affirmed, Secretariat, and some of our past Triple Crown winners, then he'll win it. If not, we'll be able to beat him."