LOUISVILLE, Ky. — International Star was scratched from the Kentucky Derby early Saturday, leaving 18 horses to run for the roses.

Owner Ken Ramsey said a problem was discovered in the colt’s left front foot, likely an abscess. The veterinarian who checked out International Star didn’t like the way he jogged inside the barn and once the blacksmith removed the colt’s shoe, a warm spot on the inside of the foot was found, Ramsey said.

International Star topped the point leaderboard that determined the 20-horse field for the Derby, having swept the three major preps at the Fair Grounds. He is trained by Mike Maker and was to be ridden by Miguel Mena.

“It’s a devastating blow to come this far,” Ramsey said in a statement. “I thought I had a decent shot at winning the race.”

Ramsey and his wife, Sarah, are among the sport’s leading owners and breeders.

“There’s nothing major wrong with the horse whatsoever,” he said. “We think we’ll probably have him ready to come back for the Preakness, but time will tell.”

The second leg of the Triple Crown will be run May 16 in Baltimore.

Five of the Ramseys’ horses set to run Saturday were scratched, including three in the Woodford Reserve Turf Classic on the Derby undercard. One of them was Stephanie’s Kitten, trained by Chad Brown. The others were Scrumpdilicious (trained by Joe Sharp) and Coalport, also trained by Maker.

“That’s an issue between me and Chad Brown,” Ramsey said. “I won’t get into that in the press, but none of the three in the Woodford Reserve will be running in our colors today.”

The Ramseys have three others set to run, including Thankyou Marylou in the Humana Distaff and Luck of the Kitten in the American Turf.

The No. 1 spot in the Derby starting gate will be left open and all the other horses will move over so there are no gaps in the gate.

International Star is the second Derby horse to be scratched. El Kabeir dropped out Friday because of a sore foot. Earlier in the week, the owners of Stanford decided not to run their colt.