Emotionless was found to be suffering with a knee injury after his disappointing run in the Dubai Dewhurst Stakes at Newmarket.
Godolphin's big hope was the chief market rival to eventual winner Air Force Blue but crossed the line in last place having been eased down by William Buick.
– #360business: Qatar Arc reflects country's passion
Subsequent X-rays revealed a chip in his left fore knee, but trainer Charlie Appleby is confident Emotionless will make a "full recovery".
"Following his disappointing run in the Dewhurst Stakes yesterday, Emotionless was found to be lame this morning in his box. He was immediately X-rayed and a chip was identified in his left fore knee," Appleby told www.godolphin.com
"I understand that its removal will not be a complicated procedure and we expect him to make a full recovery.
"We will be looking towards the trials in the spring, all being well."
Golden Horn and Frankie Dettori punctured Treve’s historic attempt to post a third straight victory in the Prix de l’Arc de Triomphe at Longchamp on Sunday with an emphatic success in the 5million euros event.
The English Derby winner beat last year’s runner-up Flintshire by two lengths, while French Derby winner New Bay edged Treve out for third.
No horse had attempted to win the Arc three times, and Treve remains in a select group of seven horses to have won the 2,400-metre contest twice.
Treve will now be retired to stud and trainer Criquette Head-Maarek may well be disappointed at the defeat, but she had no regrets.
“It is always disappointing when you get beaten as you are always here to win,” she said.
“I thought Dettori rode an incredible race. Forget Treve, she was beaten by a really good horse. There is no disgrace to be beaten by horses such as that and there are no excuses.
“She deserves to go to stud. I look forward to seeing her babies.”
It was a fourth win in Europe’s showpiece horse race for Dettori, who had previously won aboard Lammtarra (1995), Sakhee (2001) and Marienbard (2003), and it was a first for trainer John Gosden.
Golden Horn has now won four Group 1 races this season, and although he required the stewards’ assistance to secure victory in the Irish Champion Stakes at Leopardstown last month Dettori believed his mount showed his true character in Paris.
— Racing UK (@Racing_UK) October 4, 2015
“Today you saw the real Golden Horn,” he said. “He is possibly the best horse I have ridden on this performance. He has put great horses to bed behind him like a great champion.”
It was a seventh run this season for the three-year-old son of Cape Cross, but owner Anthony Oppenheimer did not rule out a final roll of the dice in the Breeders’ Cup Turf at Keeneland in America at the end of the month.
“If you have a good horse you have to race it and enjoy it,” he said. “He is certainly not going to race on next year.”
As soon as the gates opened Gregory Benoist pushed up Shahah, owned, like Treve, by Al Shaqab Racing, to set a even pace.
Dettori kept his mount straight as they emerged from their wide starting gate in stall 14 and for around 300 metres Golden Horn raced alone away from the main pack who gravitated towards the rail.
Slowly, the Italian angled Golden Horn towards the other runners and eventually took up a position behind Shahah.
Textbook stuff from Frankie there – took no chances. #GoldenHorn
— Laura King (@LauraKingDXB) October 4, 2015
They were pursued by New Bay, the French Derby winner widen by Vincent Cheminaud, while Maxime Guyon kept tabs on them on the inside aboard Flintshire.
Jarnet positioned Treve, who had uncharacteristically broken slowly, in 10th place, three horses off the rail and as they entered the false straight the five-year-old mare began to show her customary signs that she was ready to pounce.
As soon as Shahah entered the home straight, Benoist looked for the safety of the far rail as his mount tired, and Dettori forced Golden Horn in to a lead which he never relinquished.
“We knew he stayed and we knew he was good,” Dettori said.
“The plan was to stay wide, and not get him too keen. When I pressed the button he just flew. At the 300m I knew I had won. He showed a turn of foot that blew me away. I thought that no horse in the world could pass me from there.
“From the 200m home I was enjoying myself. He was like a rocket.”
Frankie Dettori's ride Golden Horn stands between Treve and her bid at Longchamp on Sunday to become the first horse to win Europe's most prestigious race the Prix de l'Arc de Triomphe for a third time.
For 44-year-old Dettori it would represent a sweet moment as the Italian was unceremoniously fired from riding French great Treve last year and then wrote off her chances for the Arc, only to have to eat his words as she romped home.
His public humiliation was worse as Qatari owner Sheikh Joaan al-Thani — for whom the Italian is still the retained rider — agreed to abide by trainer Criquette Head-Maarek's decision to fire him.
Treve's form this term has been unreproachable — far better than pre-Arc last year — winning all of her three races — not a bad effort for a horse who Head-Maarek bought back for 22,000 euros ($24,700) when her family, who had bred her, put her up for sale as a yearling.
Now a five-year-old, the decision of her Qatari owner Sheikh Joaan al-Thani and Head-Maarek to change their minds over retiring her after last year's Arc has proved the correct one.
Head-Maarek, for whose family the Arc is part of their DNA with her grandfather having trained a winner, her trainer father Alec welcoming home the winner four times and brother Freddie winning the race four times as a jockey, is phlegmatic about making history.
"If she wins three Arcs, I agree that she is (the greatest racemare of all time). Of course, but records are to be beaten," she said.
Dettori, though, has a terrific chance to upset the home support in what will be the last running of the Arc before it goes on its travels as the creaking old stands of Longchamp are torn down and given a much-needed and long-awaited overhaul.
Drying ground this week has seen Treve ease from odds-on favourite to odds against and Golden Horn shorten after the Epsom Derby winner was supplemented on Thursday making his owner Anthony Oppenheimer 120,000 euros poorer.
Winner of six of his seven starts he will have the good ground he revels in, and on which he likes to hear his hooves rattle, setting up as good a chance as his English trainer John Gosden has had of at last landing the Arc.
For Dettori it would be a fourth success and represent another remarkable chapter in the charismatic Italian's career, which looked to be ending ingloriously when in December 2012 he was suspended for six months after testing positive for cocaine at a race meeting at Longchamp.
Dettori believes that Golden Horn can deliver him a win to savour, though he predicts a tough battle with Treve.
"He's (Golden Horn) very tough and hard, but also calm," he told The Guardian. "Golden Horn's up there with the very best in the world."