Gronkowski’s trip to the Kentucky Derby has been spiked. According to a press release put out by his majority owner, Phoenix Thoroughbreds, Gronkowski has a slight infection and will miss the May 5 Kentucky Derby. Combined with news on Monday that Arkansas Derby runner-up Quip will bypass the Derby, that allows both Combatant and Instilled Regard into the Derby field. The press release said Gronkowski spiked a fever over the weekend and had to be treated with antibiotics, preventing him from traveling from England to Churchill Downs for the Derby. Gronkowski is named for Rob Gronkowski, the popular tight end for the New England Patriots. Last week, only days before Gronkowski is said to have spiked his fever, it was announced that the football player had bought an interest in the colt. :: ROAD TO THE KENTUCKY DERBY: Prep races, point standings, replays, and analysis The colt made the Derby field by topping the stand-alone European Road to the Derby series. He won the Burradon Stakes at Newcastle in his most-recent start. Churchill Downs can extend invitations to the top four in order on that European list. But the second horse is Mendelssohn, who qualified for the Derby via a victory in the United Arab Emirates Derby – part of the main Road to the Derby series – and the third- and fourth-place horses on the European list previously were ruled out of the race. So, the European series will not have a representative out of its inaugural year. And the Japan Road to the Derby series has failed to produce a runner in its two years Combatant and Instilled Regard had been 21st and 22nd on the points list Sunday night, but they moved into the top 20 with the defections of Gronkowski and Quip and both are scheduled to run in the Derby. Trainer Steve Asmussen said Ricardo Santana Jr. will retain the mount on Combatant for the Derby. Combatant most recently was fourth in the Arkansas Derby behind Magnum Moon, who is the co-second choice on the Derby future line set by Mike Watchmaker, Daily Racing Form's national handicapper. Asmussen said Combatant would have just one pre-Derby work, next Monday, April 30. Asmussen often works his horses nine days after a race, but said he decided to bypass a workout on Monday morning at Churchill Downs since Combatant would be coming back for a race in just 21 days. “Fitness is not an issue," Asmussen said. "A half in 52 isn’t going to make the difference in whether or not he wins the Derby.” Instilled Regard most recently was fourth in the Santa Anita Derby behind the Derby favorite, Justify. Snapper Sinclair is 21st on the points list, and becomes the bubble horse. Although he is expected to run in the American Turf, Jeff Bloom, who manages the partnership that owns Snapper Sinclair, on Monday afternoon said he "wouldn't rule out" the Derby. "It's a fluid situation," said Bloom, who earlier Monday said, "We'll be sticking with our plan to run in the American Turf." Blended Citizen is now 22st on the points list. He will run if he can get in, trainer Doug O’Neill has said. Entries for the Derby are to be taken the morning of Tuesday, May 1, with posts drawn later that day. In addition to the 20 horses in the main body of the race, up to four also-eligibles are allowed.