A winner of four of his six starts, Gronkowski is unbeaten this year.
"Based on his two workouts, he's made to go a mile and a half on the dirt to me," Chad Brown told TDN.
"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.
"I could have squeezed three breezes in, but I just didn't feel the horse was completely acclimated over here yet, so I went with caution and did two works. I wanted to make sure he was ready to work, and he was. Based on what I see, he looks pretty fit. There's some unknowns--he did miss some time- -and coming off a layoff going a mile-and-a-half, that's about as tough of a task as you can ask a horse to do. But he's a highquality horse, so maybe he's good enough to do it."
Gronkowski was a $75,000 Keeneland November weanling, then a 50,000 Tattersalls October Yearling, who then made 300,000 guineas at the Tattersalls Craven Breeze Up Sale when bought by Kerri Radcliffe Bloodstock and runs for Phoenix Thoroughbreds.
Gronkowski is the first winner for unraced Four Sugars, a half-sister by Lookin at Lucky to US Group I winner Flashy Bull and stakes-winner Pink Viper.
Lonhro has sired some 76 stakes-winners worldwide, but a Group I winner at 2400m metres would be a first for the champion Darley based sire.