Mohaather has been ruled out of the QIPCO 2000 Guineas at Newmarket.
Having rounded off last season with victory in the Horris Hill at Newbury, the Marcus Tregoning-trained colt emerged as a serious contender for the first colts' Classic of the the new campaign when returning to the Berkshire venue to run out an impressive winner of the Greenham Stakes.
However, Tregoning revealed on Friday that his stable star had met with a setback and connections have now confirmed he will not line up on the Rowley Mile next Saturday and could be out of action for some time.
Angus Gold, racing manager to owner Hamdan Al Maktoum, said: "He's not going to make the Guineas, sadly.
"The vet tells me it's bone bruising on his off-fore. We'll have to X-ray it again in another couple of weeks and we'll have a better idea of where we stand then.
"It's a strange one as these things tend to be a cumulative injury, but he'd shown no signs of lameness until Friday.
"He's going to need a period out of training - possibly a couple of months.
"It's disappointing, obviously. Hopefully we'll get him back in the autumn."
The leading owner is still set to be represented in the 2000 Guineas - a race he has won twice before with Nashwan (1989) and Haafhd (2004) - with Gold confirming the Kevin Prendergast-trained Madhmoon an intended runner.
"I hardly dare whisper it, but that is the plan at the moment," Gold added.
Meanwhile, Martyn Meade can hardly wait to unleash Advertise, who he believes has been overlooked by the betting public.
The colt was runner-up to Calyx in the Coventry Stakes last summer and went on to claim top-class success in Ireland before signing off for 2018 with a creditable second behind Too Darn Hot in the Dewhurst Stakes at Newmarket.
Adverise enjoyed a racecourse gallop on the Rowley Mile course at the Craven meeting and his trainer is in a positive mood going into the weekend.
He told the Racing Post: "Advertise is a Group 1 winner and he's been beaten only twice under difficult circumstances.
"When he was beaten in the Coventry he was on the far side and he didn't realise Calyx was on the other side, and in the Dewhurst he got caught a bit flat-footed when he went into the Dip. He's got every right to be there.
"We're raring to go, we haven't had any hold ups and his preparation has gone very smoothly. His price is extraordinary but I suppose people will get a bit of value – he's had a racecourse gallop and I couldn't be more pleased with him."