Connections of Zawraq have warned the colt is not certain to line up in Saturday's Investec Derby after suffering an injury scare on Tuesday morning.

he Dermot Weld-trained runner is among the leading fancies for the Epsom showpiece but after completing a satisfactory piece of work, he was found to be slightly lame on his return to the yard.

"He did a bit of work this morning with Pat Smullen up, he did it fine and walked back to the yard OK but when the head lad came back into his box, he just thought he took a lame step," said Angus Gold, racing manager to owner Sheikh Hamdan Al Maktoum .

Zawraq is prominent in the Derby ante-post lists after impressively winning his two starts to date.

Gold said: "He did his work fine, had a pick of grass back at the yard, but they just felt he wasn't 100 per cent when they trotted him up.

"He has been taken to the vets for an X-ray and scans and they came back fine, they didn't show up anything apart from a small mark on the inside of his near-fore cannon bone, so hopefully he has just given himself a knock.

"He's being iced and hopefully he's just given himself a bang, but we will obviously know more over the next 36 hours or so.

"It was his final piece of work so he's done everything he needs to do and is a fit horse.

"We are hoping to get him to the Derby but we just wanted to make everyone aware of what has happened.

"We'll see if anything comes to light in the next 36 hours."