Trainer John Moore (pictured) is not conceding a third straight Stewards' Cup win to champion miler Good Ba Ba this Sunday, despite confirming yesterday that Happy Zero will miss the race. The Hong Kong Mile runner-up emerged from his third to Able One in last week's star-studded Sha Tin trial session with mucus and traces of blood in his trachea and Moore will not risk Happy Zero this weekend. 'Especially over the mile, there's extra stress on their lungs so I won't take any chances with him - he's too valuable,' he said yesterday. 'At this time of year, when the weather is changing, all of the horses do seem to be very vulnerable to this sort of thing. 'There wasn't much blood, but I think the right thing to do is to freshen Happy Zero up and come back to the 1,200 metres of the Chairman's Sprint Prize.' Moore said Happy Zero would again trial on February 9 before taking his place in the Group One sprint on February 21, but he still expects his yard to provide a major obstacle to Good Ba Ba on Sunday with three entries - Able One, Collection and Eyeshal. 'We know the mile is a fraction short for Collection, but he is fit and fresh and Good Ba Ba will have to be right on his game to beat him,' he said. Moore has also switched course with reigning Horse of the Year Viva Pataca, who has been third in the past three runnings of the Stewards' Cup on his way to an unlucky second and then successive wins in the Hong Kong Gold Cup (2,000 metres). 'We've decided to wait an extra week with him, keep him to a bit longer and run in the Centenary Vase over 1,800 metres on February 7 as his lead-up to the Gold Cup three weeks later,' he said, but added that the remainder of his high-class team was fit and well. Moore will also saddle up three runners in the Group One Kent & Curwen Centenary Sprint Cup (1,000 metres) this weekend - the first leg of the Hong Kong Speed series - with One World, Craig's Dragon and Dim Sum. The early Centenary Sprint Cup entries were reduced by one when the final list was published yesterday, with Tony Cruz-trained Medic Power, scratched with a hind leg injury this month, no longer among them.