An injured foot has forced Santa Anita Derby runner-up Hoppertunity out of Saturday's Kentucky Derby at Churchill Downs.

.Trainer Bob Baffert was forced to scratch the Rebel Stakes winner and 6-1 second-choice from the Derby after the post draw due to a bruised left foot.

We're pretty sure it's the foot but we just want to make sure that it's nothing else, so we can continue on with him for the Preakness Stakes," Baffert said.”

"The timing is obviously horrible because we don't have enough time to work on the foot."

Baffert said Hoppertunity was sore and a portion of his hoof had been cut away.

Hoppertunity was shipped from Louisville to a Lexington equine hospital on Thursday to undergo a

Baffert said if Hoppertunity only has a bruised foot he should be able to make the Preakness on May 17 at Pimlico.

“We felt comfortable withdrawing him and getting him scanned to make sure what we have,” said Baffert, a three time Kentucky Derby winner.

“They're athletes and these things happen. Now we have to get him right.

“I'm disappointed for the owners. They're all here and were looking forward to a big race."

Baffert still has the Sunland Park Derby winner Chitu in the Derby.

Hoppertunity's scratching brings the Kentucky Derby's recently added also-eligible list into play for the first time and will give a start to the Wesley Ward-trained and Coolmore-owned Pablo Del Monte if they want to take up the option.

Pablo Del Monte will start from the outside barrier 20 if they elect to start.

Hoppertunity was the 6-1 second choice on the morning line for the Derby.

Churchill Downs put out a new odds board with Wood Memorial Stakes winner Wicked Strong now the 6-1 second choice behind 5/2 favourite California Chrome.

Arkansas Derby winner Danza and Risen Star Stakes winner Intense Holiday, both trained by Todd Pletcher, are now into 8/1 co-third choices.

Santa Anita Derby hero California Chrome was assured of favouritism after he drew post 5 while Wicked Strong will have to overcome gate 19, coming in one hole due to Hoppertunity’s scratching from gate 11.

California Chrome will be ridden by Victor Espinoza, who was aboard War Emblem when victorious from the five gate in the 2002 Derby.

Wicked Strong’s trainer Jimmy Jerkens said the wide gate will work in favour of his colt as he can be fractious in the gates and being one of the last to load will minimize the time he will have to stand in the stalls.

Louisiana Derby hero Vicar's In Trouble, to be ridden by Rosie Napravnik, wil attempt to be the first Derby winner from the rails draw since Ferdinand in 1986.

$US2 million Kentucky Derby 

Post Horse Jockey Trainer Odds

1. Vicar's in Trouble  Rosie Napravnik/Mike Maker 20-1.

2. Harry's Holiday  Corey Lanerie/Mike Maker 50-1.

3. Uncle SighIrad Ortiz Jr.Gary Contessa 30-1.

4. Danza Joe Bravo/ Todd Pletcher 8-1

5. California Chrome  Victor Espinoza/Art Sherman  5-2

6. Samraat  Jose Ortiz/Rick Violette Jr.  15-1

7. We Miss Artie  Javier Castellano/Todd Pletcher  50-1

8. General a Rod  Joel Rosario/ Mike Maker 15-1

9. Vinceremos  Joe Rocco Jr./Todd Pletcher  30-1

10. Wildcat Red  Luis Saez/Jose Garoffalo  15-1

11. Hoppertunity Mike Smith/Bob Baffert SCRATCHED

12. Dance With Fate Corey Nakatani/Peter Eurton  20-1

13. Chitu  Martin Garcia/Bob Baffert 20-1

14. Medal Count  Robby Albarado/Dale Romans  20-1

15. Tapiture  Ricardo Santana Jr./Steve Asmussen 12-1

16. Intense Holiday  John Velazquez/Todd Pletcher  8-1

17. Commanding Curve  Shaun Bridgmohan/Dallas Stewart  50-1

18. Candy Boy  Gary Stevens/John Sadler  15-1

19. Ride On Curlin  Calvin Borel/William Gowan  15-1

20. Wicked Strong  Rajiv Maragh/James Jerkens  6 -1

21. Pablo Del Monte  Jeffrey Sanchez/Wesley Ward  50-1