LOUISVILLE, Ky. - Hall of Fame trainer D. Wayne Lukas got his wish. Optimizer will run in the Kentucky Derby.

Lukas, a four-time Derby winner, was on the outside looking in until Tuesday. The top-20 Derby entrants based on graded stakes earnings are assured spots in the race. Optimizer was No. 21.

Then came news that Mark Valeski was pulling out, opening the door for Optimizer to slide into the 20th and final slot. The addition of Optimizer means that nine of the 13 horses that ran at Churchill Downs in the Breeders' Cup Juvenile last fall will return for the Derby.

Lukas will face three of his former assistants: Todd Pletcher (El Padrino and Gemologist), Kiaran McLaughlin (Alpha), and Mike Maker (Hansen).

Trainer Larry Jones was unenthusiastic about running Mark Valeski, and finally opted to skip the Derby in favor of the Peter Pan Stakes at Belmont Park on May 12.

"This is a very deep field," Jones said. "We feel like we belong with them, but there's going to be a horse that runs 15th that's a very good horse. We do feel like he's a Derby horse, but we don't feel like he's a Derby horse this Saturday. It's just not worth it right now. I think he's going to get better."

The defection of Mark Valeski could mean there will be no female jockey in the Derby unless Rosie Napravnik picks up another available mount.

My Adonis now becomes the bubble horse, moving up one spot to 21st on the graded stakes list. Upon learning that Mark Valeski was out, trainer Kelly Breen loaded My Adonis onto a van at New Jersey's Monmouth Park for the trip to Kentucky.

Double-teamed. Sabercat and Daddy Nose Best, the two Derby contenders for trainer Steve Asmussen, hit the track Monday for their final workouts. Sabercat, third in the Arkansas Derby in his last race, went a half-mile in 48.40 seconds. Daddy Nose Best, the Sunland Park Derby winner, was clocked in 49.40 for the same distance.

Asmussen said Sabercat would have to step up his game.

"He needs to be a little faster," he said. "I like his experience, but I think he's a horse that's going to have to run faster than he has to this point."

Two more works. Creative Cause and Liaison also worked Monday. Creative Cause, second by a nose in the Santa Anita Derby, appeared to have retained his edge with a swift half-mile in 47.80 seconds.

"It was perfect in my book," trainer Mike Harrington said. "I wanted him to show he was on his game, and he did it fairly easily."

The 71-year-old trainer is happily tucked away in a nondescript barn lacking a view of the Twin Spires.

The gray-roan colt has never finished out of the money in any of his eight career races, posting four wins, two seconds, and two thirds. He is among the best of five strong California-based horses in the expected 20-horse field. Of course, trainers Bob Baffert and Pletcher hold their usual strong hand, with two horses each in the 138th Derby. Harrington has his first.