Star stayer Dominant seems certain to be withdrawn from today's Longines Jockey Club Cup after pulling up lame following a routine morning exercise, throwing John Moore's Hong Kong Vase dreams into disarray and putting any overseas plans for the expensive import on hold.

Moore's powerful team for the three international day trials at Sha Tin is likely to be reduced to 14 runners as Dominant faces a regulatory vet check this morning, the result of which seems a formality; bone scans later this week will determine the severity of the stallion's injuries.

"I'm pretty doubtful he will be passing a vet check, but because there are no reserves for the race the owners would prefer to put him through that," Moore said.

"He did some light work and his lameness progressed to a two out of five. We went over him with a fine-toothed comb. There's no swelling and it just looks like something that could be higher up in the hind-quarters."

Even if scans reveal a minor problem, there are no race options in the schedule to give the 114-rated galloper another fitness-building run before the Vase (2,400m) on December 9, and if more serious problems are found, then the trainer's plans of taking the horse to Melbourne for the 2013 Spring Carnival could be dashed.

"If it came up with something like a hairline fracture, that would be a 'box-rest' job and a serious setback to any long-terms plans as well," he said.

Moore remained upbeat about his day, for which he will have 21 runners across the 11-race card.

"I've still got a super hand," he said, nominating Packing Whiz as the horse to beat in the cup race and dispelling doubts about the former Italian galloper tackling 2,000m for the first time. "He couldn't be better. He is peaking right now and I'm more than pleased with his progress," Moore said.

Of the five horses entered in the Jockey Club Sprint, Moore chose Time After Time as his best hope, believing a hot speed could give his rising star the drop on some of his more seasoned opposition.

"[Jockey] Douglas Whyte is quite keen on his chances - and given the speed they're going to go up front, that would offer itself up to closers and fit right into his run pattern," he said.

The five Moore runners in the Jockey Club Mile all face the short-priced Ambitious Dragon, and the highest-rated of his entrants, Xtension, comes in off a setback and first-up for five months.

"He'll go into the race underdone and I'll be advising Brett Prebble to ride him the same way he'll be riding Lucky Nine - to not cut him in half," Moore said.

"We know he will progress out of this run and on to the mile. He is such a genuine horse who doesn't know how to run a bad race, and he should be there when the whips are cracking. I've always said Military Attack is a Group One horse, while Dan Excel is just about at his mark and Destined For Glory has soundness issues.

"But Packing OK is a dark horse. His last run gave me a nice insight into how to train him - we've got to keep him fresh. He got the gun run the other day and should get something similar from a nice draw."