By Geoffrey Riddle and Oliver Brett
Ulysses was ruled out of Saturday's Breeders' Cup Turf on Friday night to due veterinary advice.
Sir Michael Stoute's challenger was a best-priced 3-1 and the four-year-old son of Galileo was primed for a big run, having skipped Champions Day at Ascot last month so as to save the Coral-Eclipse and Juddmonte International winner for Del Mar.
Ulysses came out of his work on Thursday with heat in his fetlock and on veterinary advice was withdrawn from the showpiece turf event.
It leaves Highland Reel in a commanding position to defend his crown from stall three under Ryan Moore, who struck for trainer Aidan O'Brien on Friday night with Mendelssohn.Highland Reel, pictured here in training at Del Mar, won last season's Turf at Santa Anita (Penelope Miller/ABR)
The globetrotting five-year-old was a brilliant all-the-way winner of the mile-and-a-half contest 12 months ago to go with his previous Group One victories in the the King George at Ascot, the Hong Kong Vase at Sha Tin and the Arlington Million in Chicago.
Highland Reel has arguably been better than ever this season, and stretched his top-level tally to six with victories in the Coronation Cup at Epsom and the Prince of Wales's Stakes at Royal Ascot.
He was most recently seen finishing a creditable third behind Cracksman in the Champion Stakes at Ascot.
O'Brien said: "At Ascot, Ryan (Moore) minded him. He kept him on the best ground and didn't hit him.
"He needed to have a run before coming here because he'd had a little bit a setback after the King George, which meant the Arc came just too soon for him.
"He's in good order. He has a good draw, he loves fast ground and loves a mile and a half.
"Highland Reel always goes forward in his races and will do that on Saturday.
"He doesn't mind bowling along, but he doesn't have to make the running. He won't mind going on himself if no one else is going to."
Highland Reel is one of three runners for the Ballydoyle handler along with Epsom Derby runner-up Cliffs Of Moher, who is still yet to register a Group One level this season, and dual Group One-winning filly Seventh Heaven.
O'Brien said: “Things haven't really worked out for him (Cliffs Of Moher) since the Derby.Cliffs Of Moher sweated up during track work at Del Mar and will be administered first-time Lasix. (Penelope Miller/ABR)
"He got badly hampered in the Eclipse, we made too much use of him at York and he got no luck in running at Leopardstown. The ground was the problem at Ascot last time, as he's a good-moving horse that just needs better ground than that.
"He seems to have come out of that well and a sharp mile and a half on fast ground should really suit him.
"The filly (Seventh Heaven) is going really well. She loves a mile and a half and loves fast ground.
"Whether the track is going to be too tight for her or not, I'm not sure, but she's in a real good place."
O'Brien has saddled a record six previous winners of the Turf.
Roger Charlton believes that the tight configuration of Del Mar will help Decorated Knight get the full 12 furlongs.
Decorated Knight, who was a 12-1 shot before Ulysses withdrawal, is one of five European challengers.
Decorated Knight will be suited by firm ground and cooler than expected weather in California and the trainer feels his star son of Galileo has adjusted well to the alien environment.
In 18 races, the five-year-old has not yet tackled a trip as long as 1m 4f but he is well drawn in stall four for Andrea Atzeni and is the only horse in the 14-runner field to have won at the highest level three times this season.
"Fast ground is definitely what suits him,” Charlton told Racing UK.
“The trip, again, Galileo - most of them stay. He's out of a mare that won over five furlongs but we know that's an ingredient Coolmore are exploiting very successfully. I thought he got the mile and a quarter plus well in Ireland. He wasn't stopping.Decorated Knight will not be administered Lasix, the diuretic with performance-enhancing properties. (Racingfotos)
"He's relaxed now, and on a tight course he's got every chance of getting the mile and a half. It was ridiculous that he went off at 25-1 in the Irish Champion Stakes. He keeps on delivering and here we go again."
Addressing the issue of mild temperatures, Charlton said it was factor that was "really good for the European horses because it's the time of year when they lose their coats a bit so you don't want to come out here and sweat a lot."
The Wiltshire handler continued: "I think some Galileos can sweat. Ulysses did, Churchill can a bit. Decorated Knight can get a bit lively on race days and I've been concentrating on keeping him as calm as possible. It was very noticeable today how relaxed he was. Andrea said there was no sign of any sweating.
"For a horse who is normally having a nice time training in Beckhampton in beautiful countryside to come here, where everything is buzzing and everyone's going in different directions is not always easy.
“But he's relaxed and that's a good ingredient. We've been wanting for fast ground all year for this horse. He's a very good mover and we've had that year when it never stops raining and we've run when the ground's not that suitable.
Brown also saddles former Marco Botti runner Fanciful Angel.
“My horses have both done really well,” Brown said.
“They came out of the Joe Hirsch in good shape.
“They seem to be training really, really well.
“They’ve had two breezes since the race and both have been impressive.
“I think they’ll both appreciate firm ground and they look like they’ll both be good at the distance.
"Beach Patrol has now proven and Fanciful Angel was coming out nicely in mile and a half so I don’t think it’ll be a problem for him. And, you know, I realize it’s going to be the toughest race they’ve ever run in. But both seem to be real high quality horses.”
Andre Fabre's Talismanic is the only European raider not to receive Lasix.