One false step will deny early favourite Quality Road a start in this weekend's Kentucky Derby at Churchill Downs.The colt jogged more than 2500 metres at Belmont Park over the weekend in an effort to prove he had fully recovered from quarter cracks in his right front hoof but a "tinge" of blood left a cloud over his campaign."He has to work to our liking and come out of it perfectly," trainer Jimmy Jerkens told RacingPost."If he takes one bad step anywhere, forget it.""He's got 24 hours to get

One false step will deny early favourite Quality Road a start in this weekend's Kentucky Derby at Churchill Downs.

The colt jogged more than 2500 metres at Belmont Park over the weekend in an effort to prove he had fully recovered from quarter cracks in his right front hoof but a "tinge" of blood left a cloud over his campaign.

"He has to work to our liking and come out of it perfectly," trainer Jimmy Jerkens told RacingPost.

"If he takes one bad step anywhere, forget it."

"He's got 24 hours to get better. I would have liked to have seen no blood, but it didn't surprise me because he was still tender.

"He's sound, he galloped the way he usually does, but I would have been more optimistic without blood."

The Florida Derby winner went around at Belmont Park with a newly-patched hoof after a second quarter crack was discovered.

Trainer Todd Pletcher said Coolmore's $US3.7 million ($A5.1 million) purchase Dunkirk, runner-up to Quality Road in Florida, was ready for the classic after working over 1000 metres on Saturday at Palm Meadows, Florida.

"We couldn't be more pleased with the way things have gone coming up to the race," Pletcher said.

Godolphin's Kentucky Derby pair Regal Ransom and Desert Party continued their low key preparations with solid workouts at Churchill Downs on Saturday morning.

Trainer Saeed Bin Suroor seemed especially pleased with Regal Ransom.

"He is going very good - he showed a good turn of foot, plenty of speed. "One and a quarter miles should be no problem for him - I think he'll stay. This horse is going the right way," he said.

Despite his hoof problems, Quality Road was still on the third line of betting when Las Vegas bookmakers updated their Derby quotes on Monday.

Sportingbet Australia had him the $9 fifth favourite.

Others at the top of Monday's Sportingbet Australia market were: I Want Revenge $4.40; Pioneerof The Nile $6.50; Dunkirk $7; Friesan Fire $8 Desert Party $10 and Regal Ransom $13.