BALTIMORE, MAY 15 -- The tender foot of Kentucky Derby winner Sunday Silence showed "considerable improvement" today, but trainer Charlie Whittingham said he will not commit the colt to Saturday's Preakness Stakes until he has seen him work out. Sunday Silence has until Thursday to put in a bona fide workout at Pimlico, Whittingham said. If the colt is unable to do so, he'll be scratched from the second leg of the Triple Crown. Although an air of optimism pervaded the Whittingham camp this morning, the 76-year-old trainer maintained his conservative posture. "He's better today than he was yesterday," he said. "But if he isn't a hundred percent, we'll wait for the Belmont." Sunday Silence left his stall this morning for the first time since it was discovered Sunday that his right front foot is bruised. He walked about the shedrow without apparent discomfort for an hour under groom/exercise rider Pam Maber. "He's really improved," Maber said. "He was favoring {the foot} before, but not now." Whittingham had intended to have Sunday Silence fitted with glue-on shoes Sunday in hope of galloping him this morning. But Sunday's forecast for two days of rain caused him to change course. Whittingham instead had Kentucky blacksmith Ric Redden put bar shoes on Sunday Silence's front feet, and the trainer chose not to send the colt onto the moist track this morning (although it was listed as fast on the workout tab). The bar shoe serves several functions: because it is nailed into the hoof, it would be more secure should Sunday Silence gallop on a muddy track Tuesday; it also allows room for protective padding to be placed over the foot and relieves pressure on the sensitive area. Whittingham said the bar shoes would be replaced by traditional racing shoes before the Preakness. Veterinarian Alex Harthill said Sunday Silence has responded quickly to treatments, limited mostly to soaks in warm water and Epsom salts. "He's made a considerable improvement," Harthill said. "We've closed a big gap in a short time." The stable was inspired that Sunday Silence has been eating well and attempting to nip passersby, his customary practice. Although X-rays of the foot Saturday showed no fracture, Harthill had considered taking more pictures today to be sure. But by morning he reconsidered, ruling out the possibility of an obscured break. Whittingham said he plans to gallop Sunday Silence Tuesday morning -- muddy or not -- and hopes to tighten him up with a four- or five-furlong workout Wednesday. The colt has galloped since the May 6 Derby but hasn't worked. Whittingham softened his position on Sunday Silence's necessity to have a brisk workout by Wednesday. "I could go until Thursday," he said. "The bar shoe will keep the pressure off his heel. We're still in good shape because this horse is ahead of himself {training-wise}." Nonetheless, the withdrawal of Sunday Silence remained a possibility today, even though it would make him ineligible for Triple Crown bonus money, worth as much as $5 million were Sunday Silence to follow his Derby triumph with victories in the Preakness and Belmont stakes. But Whittingham is concerned about physical condition more than fiscal condition -- he owns the colt with Arthur Hancock and Ernest Gaillard -- and he appears unwilling to budge. "Maybe we could let him pull the starting gate for this one," he joked. In addition to Sunday Silence, Hawkster remained a viable Preakness candidate for another day. Trainer Ron McAnally arrived from California late this morning -- fog diverted his landing from Baltimore to Norfolk -- and said he, too, would like to see his colt on the track before deciding on Saturday's race. Hawkster has an injured left front foot, which McAnally suspects was incurred after his late-running, fifth-place performance in the Derby. McAnally said he noticed that Hawkster's shoe was wrenched as the colt grazed the morning after the Derby. "I got the blacksmith, and he put the nail in the {hoof} three times," McAnally said. "He said he couldn't get the right hole. He wanted to get the old hole, and he might have gotten it too close to the quick." X-rays showed nothing serious, but McAnally said the colt has some heat in the area. He hopes to gallop Hawkster Tuesday. "We'll put a little pressure on it," he said, " . . . and maybe something will show up." If both Sunday Silence and Hawkster run Saturday, the Preakness still might have only seven horses. The status of Rock Point, a possible eighth, should be decided Tuesday, according to trainer Sid Watters.