Unfazed by the wide gate, oddsmakers posted the three-year-old, who won last month's Florida Derby, at the top of the betting charts at 7-2.
"I'd love to be the favourite," Orb's trainer Shug McGaughey said after the colt's morning gallop. "I wish every one of my horses was favourite. They're not all going to win, I understand that, but I'm on board with that."
The unbeaten Verrazano, whose four career wins include the Tampa Bay Derby and the Wood Memorial, was listed as the second choice, at odds of 4-1.
He is one of five runners trained by Todd Pletcher. The others are Overanalyze, Revolutionary, Palace Malice, and Charming Kitten.
"They all did the exact same things," Pletcher said when asked to compare their morning workouts.
"They all galloped a mile and three-eighths and they all stood in the starting gate. Everyone did well."
Goldencents, the winner of last month's Santa Anita Derby, was posted as the 5-1 third chance after drawing the eighth post. His trainer Doug O'Neill won last year's Kentucky Derby with I'll Have Another.
Lines of Battle, the Irish-trained colt who secured his place in the race by winning the United Arab Emirates Derby, drew 11 while Black Onyx landed the dreaded number one position.
It has been a quarter of a century since a horse drawn on the rails has won the mile and a quarter (2000 metres) race.
A total of 21 horses were entered for the race with Fear The Kitten listed as an alternate entrant should any of the 20 runners scratch before Friday morning.