It was the Chad Brown trainee's second work since arriving at Belmont, following a four-furlong breeze May 26 in :47.99. Jockey Jose Ortiz, who will have the call on Gronkowski in the Belmont Stakes, was in the irons again.
Gronkowski worked in company with Engage, who is targeting the Woody Stephens presented by Mohegan Sun (G2), also on the June 9 card.
"It went well. (He) galloped out a good three-quarters, and I was real happy with it," Brown said of Gronkowski. "This horse hasn't put a foot wrong since he's arrived. He's a real classy horse and came to me in outstanding condition."
The Lonhro colt will make his first North American start in the Belmont after he went 4-1-0 in six races in England.
"Based on his two workouts, he's made to go a mile and a half on the dirt to me," said Brown, who took over training duties from Jeremy Noseda in May. "In a perfect world, I wish I had him longer and had a better handle on the horse, but it is what it is, and I'm fortunate to be in this position to go there with a chance to win."
Gronkowski was scheduled to work June 1, but a driving rainstorm led Brown to move the work.
"I was ready to breeze him yesterday, but then the rain came. But it worked out," Brown said. "Today was always the day I preferred to work him anyway."
Later Saturday at Belmont, SayJay Racing, Greg Hall, and Brooke Hubbard's Blended Citizen, winner of the May 12 Peter Pan Stakes (G3), breezed five furlongs in 1:00.64 over Belmont's main track just before the first race.
The two-time grade 3 winner took to the track alongside a pony at 12:45 p.m. in a special time reserved for the Doug O'Neill trainee.
Under jockey Mike Luzzi, Blended Citizen began from the half-mile pole and ran the first eighth in :12.65, a quarter in :24.25, hit the wire in :47.93, and finished his drill a furlong past the wire. New York Racing Association clockers caught Blended Citizen galloping out to six furlongs in 1:17.58.
"He covers a lot of ground. He's a Cadillac," Luzzi said. "Obviously, we know he likes the track. I wish the best of luck to them next week."
Assistant trainer Leandro Mora traveled from California to oversee the Proud Citizen colt's workout and was pleased with the style and ease the multiple graded stakes winner offered.
"What I like is how easily he did it," Mora said. "It was nice. I'm very pleased. He wasn't even making noise going by. I like how he went past the wire. That's when you know you have a legit horse. I like what I saw."