He cemented himself as the leading contender after winning by an astonishing 19 1/4-lengths margin at September's Pacific Classic and is expected to send jaws dropping again over the same 1 1/4-mile distance in Lexington, Kentucky.
"The mile and a quarter, that was the question before the Pacific Classic and he answered that," trainer John Sadler said in remarks provided by race organisers. "There's not much more I can say."
Flightline's morning line odds were set at 3-5 Friday, when he was scheduled to wrap up his preparations on the dirt track.
While he hardly needs the help - after all, the buzzy bay colt won his five career wins by a combined 62 3/4 - he'll have the aid of 2021 Preakness Stakes and 2019 Kentucky Derby winner Flavien Prat in the saddle out of post position four.
But there several recognisable names ready to spoil his trip to horse racing lore, with the Bob Baffert-trained Taiba fresh off a win at the Pennsylvania Derby in September. He starts out of the first position with 8-1 morning line odds.
Hot Rod Charlie, last year's Belmont runner-up, has a shot at 15-1 and this year's wildly improbable Kentucky Derby winner Rich Strike will try again to beat the odds - and overcome his unfavourable outside post position - at 20-1.
Flightline's biggest competition in the $6million classic, however, may come from the 5-1 Epicenter, who settled for second at Churchill Downs and Pimlico earlier this year.
"If he beats the older (horses), he's fortunately Horse of the Year," said trainer Steve Asmussen.
"Having the best horse in training, what is there to be more proud of? The opportunity is there. And is it easy? Absolutely not. Should it be easy? Absolutely not."
The Breeders Cup Classic is set for Saturday at 5:40pm ET (22:40 CET).
