Connections will now have to snuffle out problems other than physical ones to explain the deterioration of the colt who was regarded as an above-average Epsom winner when beating King's Theatre, the subsequent King George VI & Queen Elizabeth Stakes victor, and Colonel Collins.
Erhaab's first setback came in the Eclipse Stakes at Sandown, where he failed to produce his customary late burst and was defeated by Ezzoud and Bob's Return. This lapse was ascribed to a hamstring injury, which recurred before the King George and put the colt's participation in jeopardy.
Erhaab recovered sufficiently to take part, but was a dispirited and tired horse even before he took a blow amidships from the riderless Ezzoud just after the field had turned in to the straight. He eventually finished seventh.
The near-black colt returned with evidence of the collision, bruising to a knee, and that was one of the areas subject to X-ray examination on the insistence of John Dunlop, the colt's trainer. But when Dunlop, whose Armenian Dancer won in Italy on Sunday, returns to his Castle Stables he will find no simple explanation for Erhaab's loss of form.
'Erhaab was X-rayed but they revealed no significant findings,' Marcus Hosgood, a stable spokesman, said. 'We don't know what will happen next. Mr Dunlop is out of the country and will have to speak to Angus Gold (racing manager to Erhaab's owner, Sheikh Hamdan Al Maktoum) and vets before they collectively plan what to do.'
The collective is expected to aim towards the Prix de l'Arc de Triomphe at Longchamp in October as a means of restoring Erhaab's reputation, and value.
Doubts are also swirling around one of Erhaab's old adversaries, Weigh Anchor. The colt was sent off fourth favourite for the Derby after chasing home Erhaab in the Dante Stakes at York, but faded badly at Epsom to finish 13th, beaten 20 lengths.
Ian Balding's colt had his supporters in the King Edward VII Stakes at Royal Ascot, but he again brought them disappointment by dribbling home seventh of eight behind Foyer. In this instance, an excuse could be found - a pulled stifle - but Balding is finding it more difficult to identify the next target for his horse.
It may be that those at the Kingsclere yard now believe Weigh Anchor does not stay a mile and a half, as his entries include the Champion Stakes over 10 furlongs at Newmarket in October.
Double Trigger, a stablemate of Mister Baileys and at one stage Mark Johnston's main Derby hope, may make his comeback from injury in the Great Voltigeur Stakes at York later this month.
Magongo, ridden by Alan Munro, gave Tereshkova, the 100-30 on favourite, a fight before going down by half a length in the Group Two Prix de Cabourg over six furlongs at Deauville yesterday. Magongo is trained at West Ilsley by Lord Huntingdon.