05/01/2007 11:00PM

Street Sense works briskly

Michael J. Marten/Horsephotos
Street Sense gets his final Derby tune-up, under regular rider Calvin Borel, Tuesday morning at Churchill Downs.

LOUISVILLE, Ky. - Like the last round of a high-stakes poker game, it was time for the last call on Tuesday on Churchill Downs. Street Sense, the likely favorite for Saturday's 133rd Kentucky Derby, raised the ante with another flawless work, while two horses, Cobalt Blue and Xchanger, threw in their cards and folded.

The defections of Cobalt Blue and Xchanger allowed both Teuflesberg and Imawildandcrazyguy to creep up on the graded stakes earnings list and move into the body of the race. Entries for the Derby were to be taken on Wednesday morning, with posts selected Wednesday night. More than the maximum 20 horses were expected to be entered in the race. The criteria in that case is . As of Tuesday, the horse first on the bubble was Reporting for Duty, who is trained by Steve Asmussen.

Asmussen also trains Derby starters Curlin and Zanjero. Curlin, who is unbeaten in three starts but did not race at age 2, and Street Sense, who won last year's Breeders' Cup Juvenile and was the Eclipse Award-winning 2-year-old male, are seen by most handicappers as the two horses who will attract the most wagering support.

But which one will be favored? Mike Battaglia, who makes the morning line at Churchill Downs, on Tuesday said he was leaning toward making Curlin the favorite at 7-2, with Street Sense next at 4-1.

"I keep wavering, but I think it's going to be Curlin, then Street Sense," Battaglia said. "Curlin was favored in Pool 3 of the Kentucky Derby Future Wager. But last year, Brother Derek was a big favorite in Pool 3, and Sweetnorthernsaint was 10-1. It's a tough call."

Sweetnorthernsaint ended up the Derby favorite last year at 5-1, with Barbaro 6-1 and Brother Derek 7-1.

Mike Watchmaker, Daily Racing Form's national handicapper, on Tuesday said he was likely to make Street Sense the favorite at 5-1, with Curlin next at 6-1.

"It seems that there is much more discussion about Street Sense," Watchmaker said. "Curlin, whenever his name comes up, it's all in the context of the historical obstacles that he has to overcome."

Street Sense's Breeders' Cup victory came six months ago at Churchill Downs, where he is based with trainer Carl Nafzger. Street Sense again showed his fondness for this track on Tuesday morning, when he worked five furlongs with jockey Calvin Borel. Daily Racing Form caught him in 1:00.68, while Churchill's clockers gave him an official time of 1:01. Regardless, Street Sense finished strongly and galloped out with enthusiasm, a workout Nafzger thought set him up for his best on Saturday.

"He did everything right," Nafzger said. "He relaxed the first part and galloped out easy. If he gets a lane, he'll be 1-2-3," Nafzger said. "If he doesn't, he'll be 7-8-9."

The Derby field underwent some last-minute adjustments on Tuesday when Cobalt Blue and Xchanger came out. Cobalt Blue, the San Felipe Stakes winner, was coming off a seventh-place finish in the Illinois Derby at Hawthorne and had subsequently turned in two poor workouts at Keeneland.

Tuesday morning at Churchill Downs, however, Cobalt Blue looked like a new horse. With blinkers added, he galloped powerfully under exercise rider Tony Romero, and at one point moved so quickly that Daily Racing Form caught him going seven furlongs in 1:26.17.

Later in the morning, though, trainer Doug O'Neill, after conferring with owner Merv Griffin, announced Cobalt Blue would not run.

"I think it all starts with the Hawthorne race - that was so disappointing," O'Neill said. "I think his last workout at Keeneland was very questionable. The time was fast, but Tony said he was just really lackadaisical.

"Merv said, 'Don't run that horse just for me. If we need to bring him back home and find a different spot, let's do it.' I put in a little bit of a plea because the colt is a talented colt, but at the end of the day it's probably the right move."

Cobalt Blue's defection put Teuflesberg into the Derby, delighting Jamie Sanders, the colt's trainer and co-owner, who had been anxiously hoping Teuflesberg would get in following his close fourth-place finish in the Blue Grass Stakes three weeks ago.

And then later Tuesday, the connections of Tesio Stakes winner Xchanger informed Churchill Downs's racing office that they were out, too. That put Imawildandcrazyguy in the Derby, giving trainer Bill Kaplan a second Derby starter, along with Storm in May. Asmussen, Darrin Miller, and O'Neill also have two starters in this Derby.

Kaplan also entered Imawildandcrazyguy in the Crown Royal American Turf on Friday as a backup, but will go in the Derby if not bumped by some last-second, unexpected horse.

"I'm very, very happy for the owners," Kaplan said. "It's a once-in-a-lifetime thing for them. But as far as I'm concerned, this is not just an opportunity to run this horse. I believe he has a tremendous cardiovascular capability. He's an endurance specialist, and the 1 1/4-mile distance will be perfect for him."

Kaplan said Mark Guidry would ride Imawildandcrazyguy.

Trainer Todd Pletcher, who was scheduled to enter five horses in the Derby, brought his four Keeneland-based runners - Any Given Saturday, Circular Quay, Cowtown Cat, and Scat Daddy - to Churchill Downs on Tuesday to join Sam P., who has been training at Churchill.

Stormello and Tiago, who arrived on Monday from California, visited the Churchill Downs track on Tuesday for light gallops.

The last Derby runner yet to come to Churchill is Nobiz Like Shobiz, who was scheduled to be flown from New York to Kentucky on Wednesday.

- additional reporting by David Grening, Byron King, and Mike Welsch