They keep looking for the signs; signs that the remarkable feats Justify has been pulling off are starting to take their toll. Logic says they should, because when a horse who is still just baby is asked to pack five races into about a 90-day span — including two of the toughest tests in his sport — at some point fatigue should start to make itself known.

Those who watched the dual classic-winning son of Scat Daddy head to the Churchill Downs track on Thursday for his first bit of training since his victory in the May 19 Preakness Stakes were left suitably impressed at the unbeaten chestnut colt’s ability to keep such rigors at bay.

With assistant trainer Jimmy Barnes watching from aboard dutiful pony Sunny, and exercise rider Humberto Gomez in the irons, Justify looked like his usual stalwart self as he galloped around a couple turns beneath the Twin Spires in preparation for his expected start in the June 9 Belmont Stakes.

“I saw just what I needed to see,” said the venerable Barnes, who is overseeing Justify’s day-to-day care with trainer Bob Baffert back at his California base. “He had a good bounce in his step, very happy. We just took it easy with him out there, went about a mile and three-eighths. Bob just wanted to give him a nice, easy first-day-back gallop, which we did. And he seemed to really enjoy it.”

That Justify has gone from debuting Feb. 18 to being one race away from becoming just the 13th horse to sweep the U.S. Triple Crown is a testament to both the exceptional training job Baffert has executed and the constitution of the colt to stand up to it. Both Baffert and Barnes have said Justify hasn’t missed an oat since his 2 1/2-length triumph in the Kentucky Derby Presented by Woodford Reserve, adding that his energy level continues to be one of the traits that pushes him into rarefied air.

“It makes it very easy for us, to have a horse that is capable of doing that,” Barnes said. “This horse carries his weight very well and he’s just made it very easy for me.”

Among those studying Justify’s frame Thursday morning was Elliott Walden, president of WinStar Farm, which co-owns the colt along with China Horse Club, Starlight Racing, and Head of Plains Partners. That collective partnership also owns Grade 1 winner Audible and is in the interesting position of having to decide whether they run a horse who figures to be a live Belmont Stakes prospect against their horse trying to make history.

Audible most recently finished a fast-closing third to Justify in the Kentucky Derby and is slated to work at Belmont Park May 25 for trainer Todd Pletcher after which, Walden said they would have a conversation about the Into Mischief colt’s Belmont status.

“Obviously, you have a Triple Crown on the line, so there are all kinds of factors to it,” Walden said of the situation.

WinStar and China Horse Club also co-own graded stakes winner Quip, whom they did start in the Preakness against Justify and watched finish last in the field of eight.

“It’s different when you’ve won two out of three than when you’ve won one out of three,” Walden said. “But at the same time, I do feel like you can’t manufacture a Triple Crown. It’s either going to happen or it’s not. We’ll see.”

One horse who is confirmed to take another swing at Justify in the 12-furlong Belmont is graded stakes winner Bravazo, who came flying in deep stretch of the Preakness and fell just a half-length short of what would have been a wild upset.

The son of Awesome Again also returned to the track Thursday for an energetic jog with trainer D. Wayne Lukas adding it has been a task to keep the colt on the ground since returning from Baltimore.

“He was really into it,” Lukas said. “He rolled around there very strong. He was wanting to get out of here before they opened [the track].”

Lukas and Baffert are now tied with 14 wins apiece in Triple Crown races. Confident as the former is that his hard-knocking charge will keep Justify honest in the final classic, Lukas says the 1 1/2-mile test is still Baffert’s to lose.

“I really felt Justify was the horse to beat, he was the best horse in the Preakness,” Lukas said. “But we got a little bit closer ... and it turned out pretty good. He’s still the best horse. We still have him to deal with, very much so. I was impressed with [Justify] this morning. When I took mine out, I was right in front of him and I told Jimmy ‘I went in front of you because that’s probably the last time I’ll be in front of you.’ ”

Tenfold (Coady Photography)

Winchell Thoroughbreds’ homebred Tenfold, third in the Preakness Stakes, also hit the Churchill Downs oval Thursday for a gallop as he readies for an expected run in the Belmont Stakes. The Curlin colt is an impressive physical specimen in his own right with a level of progression trainer Steve Asmussen expects will only improve as the year goes on.

“We have a tremendous amount of confidence in him and I think what we’ve seen is just the edge of it,” Asmussen said. “Who he is right now and who he’ll be in two and a half weeks I think is nothing compared to who he will be next year. I think it’s just all ahead of him.

“This [the Belmont] will be a true test to that [coming] off his lifetime best, wheeling back in three weeks when he doesn’t have a bunch of races in him. But I love his attitude. It’s very consistent. He’s such a beautiful mover.”