Champion jockey Joao Moreira may get the opportunity for a return to the seat on impressive Hong Kong Derby winner Ping Hai Star in the Audemars Piguet QE II Cup with the announcement that Aidan O’Brien will have a runner in the race.

The Jockey Club has released the invited field for the HK$24 million feature, with eight top local middle distance horses joined by three runners from overseas, including the O’Brien-trained War Decree.

War Decree is raced in an ownership that includes several principals of Coolmore Stud and Ping Hai Star’s Derby-winning jockey Ryan Moore is the primary rider for O’Brien and Coolmore.

If Moore is held to riding War Decree for them, that would open up a vacancy on the John Size-trained Ping Hai Star for Moreira, who won three in succession on the four-year-old before having to make the choice between him and another regular ride, his stablemate Nothingilikemore, in the Derby.

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He stuck with Nothingilikemore, Moore took over on Ping Hai Star and the gelding came from last for one of the best Derby wins of recent seasons.

The Brazilian, in turn, would have to get off quirky Pakistan Star to take the Ping Hai Star mount but the Tony Cruz-trained five-year-old is not yet guaranteed a place in the QE II Cup.

Although he appears in the list of selected runners, Pakistan Star’s patchy willingness to run mid-race in Sunday’s Chairman’s Trophy saw the stewards impose a requirement to barrier trial over 1,600m to their satisfaction before he runs next.

The Jockey Club announced on Monday that a 1,600m heat has now been added to the schedule for Friday-week’s trial session, which looks the stage for Pakistan Star’s test.

However, any failure to pass there would leave him no second opportunity to meet the stewards’ order and he would miss the QE II, the race in which he was runner-up to Japan’s Neorealism last year.

War Decree’s form at home includes a two-year-old Group Two and a Group Three on Dundalk’s polytrack at three but he was a well-held 10th to Time Warp in the Hong Kong Cup in December and his only appearance since was a ninth in the Dubai Turf on World Cup night.

The two Japanese horses, however, appear to be in competitive form after filling third and sixth placings behind Suave Richard in the recent Group One Osaka Hai at Hanshin.

The Hidetaka Otonashi-trained Danburite led in to that race with a Group Two win in January, while Yasutoshi Ikee brings Al Ain, last year’s Japanese 2000 Guineas winner and Derby fifth who has been placed at both 2018 starts.

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Otonashi has had just one previous Hong Kong runner, Mikki Isle, who was seventh in Peniaphobia’s 2015 Hong Kong Sprint, while Ikee has had six runners without success at Sha Tin.

There were no surprises in the local invitees, headed by Hong Kong Cup winner Time Warp, the Hong Kong Derby winner, third and fourth, Ping Hai Star, Exultant and Ruthven, as well as recent feature race winner Eagle Way, Gold Mount and Dinozzo.

In the HK$18 million Champions Mile (1,600m), O’Brien provides the only foreign invitee, Lancaster Bomber, who was a sound fifth to Beauty Generation in the Hong Kong Mile in December.

The HK$16 million Chairman’s Sprint Prize (1,200m) has three invited runners based overseas, two of them under the Godolphin banner – Japan-based Takamatsunomiya Kinen hero Fine Needle as well as the Charlie Appleby-trained Blue Point, scratched on race day at the Dubai World Cup when a short-priced favourite for the Al Quoz Sprint.

O’Brien will also be represented in the Sprint with Washington DC, who finished fourth to Blue Point’s stablemate Jungle Cat in the Al Quoz.

John Size has dominated sprint events this season and will saddle up five of the 12 invitees for the Chairman’s Sprint Prize, with Ivictory and Thewizardofoz joining his three starters from the Sprint Cup at Sha Tin on Sunday, Beat The Clock, Mr Stunning and Amazing Kids.