New England Patriots star Rob Gronkowski's race horse has been withdrawn from the Kentucky Derby after developing a fever, the three-year-old's owners said Tuesday.
Larger-than-life tight end Gronkowski had announced earlier this month that the horse -- "Gronkowski" -- would run at Churchill Downs.
However the horse's ownership group Phoenix Thoroughbreds said Tuesday that a sudden illness over the weekend meant he would not be fit to race.
"It's unfortunate Gronkowski the horse will not be able to race in the upcoming Kentucky Derby due to an illness," Gronkowski wrote on Twitter.
"I fully support what is best for the horse. I know he will come back strong and healthy and I am excited to see him race again very soon."
Phoenix Thoroughbreds said Gronkowski was responding well to antibiotics.
"He can't make the long journey to Louisville but is doing well," the ownership group said.
Gronkowski was undefeated in three races this year. This year's Kentucky Derby takes place on May 5.