Winner of the King George VI And Queen Elizabeth Stakes at Ascot last summer, when trained by Luca Cumani, the five-year-old was subsequently moved across Newmarket with the rest of owner Sheikh Obaid's string to Roger Varian's stable.
Back-to-back victories at the Dubai Carnival saw him make a flying start for his new handler and he looked well positioned to dominate the mile-and-a-half division this summer after a spectacular return to Britain in the Coronation Cup at Epsom in early June.
However, he was unable to defend his King George crown after suffering a respiratory infection, a condition which also affected several of his stable companions.
Consequently, Varian has so far saddled just 10 runners in August compared to 68 in 2015.
"Half the battle is recognising it and not doing too much with the horses if they are slightly under the weather," Varian said.
"We've been cautious with what we have run but we managed to get a nice winner at Doncaster on Saturday and hopefully we are close to hitting form again.
"It's challenging, but hopefully Postponed can give us a boost. He's been training well over the last few weeks, looks great and seems right back to himself.
"Horses are no different to people, in that one person might take longer to get over an illness than another living next door.
"Postponed is a big five-year-old with a good constitution and he looks to have recovered quicker than some.
"He's in his prime and one of the best around.
"It was disappointing to miss the King George but by no means the end of the world."
Postponed will be bidding for a first Group One victory over a mile and a quarter, something which would significantly boost his commercial value as a potential stallion.
Varian does not feel the drop in distance will be a major issue.
He said: "This year he has travelled very strongly in his races and, most importantly, Andrea (Atzeni), who gets a number one feel of the horse, thinks he will handle himself down in trip very comfortably.
"Also, the majority of the horses in the field have perhaps shown their best level of form at a mile and a half, so he is not the only one with it to prove at a mile and a quarter."
One horse with no questions to answer regarding the distance is Godolphin's Hawkbill, who is unbeaten in three starts over a mile and a quarter this season.
He completed his hat-trick with a narrow verdict over subsequent Sussex Stakes winner The Gurkha in the Coral-Eclipse at Sandown.
Godolphin racing manager John Ferguson said: "The great thing about it is it's a mile and a quarter, which we know he loves.
"He's very flexible as far as ground conditions are concerned.
"And although he is taking on some of the best mile and a quarter horses in Europe, we believe he deserves to be there.
"Charlie is very happy with him. He is a horse that is maturing mentally all the time.
"They've done a great job with him and I think he will run well."
Aidan O'Brien and Sir Michael Stoute have won this prize a joint-record five times and both fire twin assaults.
O'Brien, who was last successful with dual Derby hero Australia in 2014, saddles King George hero Highland Reel and the fourth at Ascot, Sir Isaac Newton.
"Highland Reel is in in good form and we've been very happy with him since Ascot," said the Ballydoyle handler.
"Sir Isaac Newton is a horse that we think is still progressing.
"He had a lovely run in the King George and we've been happy with him since."
Stoute's last International victory was secured by Notnowcato a decade ago .
He is represented by Arab Spring, third on his belated seasonal debut in the Rose of Lancaster Stakes at Haydock, and Exosphere, who occupied the same position in the Princess of Wales's Stakes at Newmarket's July meeting.
Stoute said of the latter: " We are putting him back to a mile and a quarter and hopefully it will suit him.
"It's a tough race but we are going to throw our hat in the ring."
Mutakayyef is an interesting contender for trainer William Haggas and owner Hamdan Al Maktoum.
The five-year-old comfortably won the Ganton Stakes at this track in June before dominating his rivals in last month's Summer Mile at Ascot.
He steps up to a mile and a quarter for the first time this season as he makes his debut at Group One level.
Sheikh Hamdan's racing manager Angus Gold said: "I think this is a learning curve as much for us as it is for everyone else.
"I'm pretty confident the trip won't be a problem. He looked like staying the mile and a quarter last year and that was before he was gelded and he started finding his form.
"William was quite keen to supplement him for the Sussex at Goodwood and stay at a mile, but Sheikh Hamdan had Awtaad in that and he decided we'd wait and go for the Juddmonte.
"He's a horse that's improved a lot this year, both physically and mentally, and York will tell us a lot more.
"I'm looking forward to seeing him run as he's now performing like the decent horse William always thought he was."
The Grey Gatsby has been placed in the last two renewals for local trainer Kevin Ryan and will be ridden by Daniel Tudhope for the first time.
Tudhope feels victory for The Grey Gatsby would "raise the roof" at York.
Fresh from his success aboard Mondialiste in the Arlington Million, Tudhope received the first-time call-up for the Kevin Ryan-trained five-year-old due to his link with owner Frank Gillespie, who has horses with the rider's boss, David O'Meara.
He said: "I'd be lying if I said it wasn't a bit of a surprise to get the call but obviously I'm really looking forward to it.
"He's finally got his ground and the big field will help - he's done little wrong this season.
"He deserves another win and as he's trained in Yorkshire it would raise the roof if he does it."
John Gosden's King George runner-up Wings Of Desire and French challenger Dariyan also feature in a fascinating contest.
Clive Cox's Prince of Wales's Stakes winner My Dream Boat is a non-runner.