Injury doubt over Caller One A last-minute injury scare may threaten the participation of American challenger Caller One at Royal Ascot next week.The Jim Chapman-trained speedster, who was to be aimed at the Golden Jubilee Stakes on Saturday week, has an abscess in his near-fore foot which is concerning connections.The five-year-old is currently based at Geoff Wragg`s Newmarket stable but the Florida trainer`s father Jim snr, who was at Ascot today to check on conditions, said he was still hopeful that Caller One would line up for the Group One prize.'He came out with a pretty bad abscess after Singapore,' said Chapman snr.'He`s training at the moment with a bar shoe and it had been really good but then on Sunday he knocked the shoe off and it got a bit of heat in it.'But it seems like it`s coming on all right and hopefully he`ll be all right.'Another potential problem for Caller One could be the forecast soft conditions.All of his best form - for example his two successes in the DubaiGolden Shaheen - has come on the dirt and his speed could well be blunted if the ground were to become muddy.'I suppose it depends just how soft it gets,' Chapman snr said.'I don`t think it was the turf that was the problem for him in Singapore. We`ve worked him plenty of times on the grass and he`s been all right.'He takes all the travel in his stride and he`s a nice horse to be around.'Nick Cheyne was in California when he first approached my son about running in this race and it fits into his programme.'If he had gone straight home after Singapore, he`d have put a lot of weight on which might have been tough to shift for the Breeders` Cup.'It`s still undecided who is going to ride him but it`s not a big issue. As I understand it, Gary Stevens isn`t going to travel over but I don`t think we would have a problem with using a European jockey.'Caller One`s stablemate Western Pride, who is also at Wragg`s yard, may bypass an intended tilt at the Queen Anne Stakes.'He had a problem with a high white blood cell count and he`s just hanging now,' said Chapman snr.'I think we`ll back up to a mile with him rather than stay at a mile and a quarter but I don`t know if he`ll run at Ascot.'