Hong Kong's highest-rated galloper and reigning Horse of the Year Werther returns on Monday with the usual reservations tendon injuries bring but also plenty of optimism from trainer John Moore.

Werther's dominant Group One Audemars Piguet QEII Cup win was named equal eighth-best performance of 2016 when the Longines World's Best Racehorse rankings were released this week.

Yet whether or not Moore's five-year-old can ever scale those heights again after suffering a suspensory injury in his right hind leg during preseason is the big question heading into Monday's Group One Stewards' Cup at Sha Tin.

"Of course there is a lot of expectation any time you have a Horse of the Year returning, especially when he has rated so highly with his performances," Moore said of the horse that is rated the equal second-best Hong Kong-trained horse since 1998.

"But the jury is out with regard to injury, so there is an element of wait and see. But he is a very clean-winded horse, like Rapper Dragon, and maybe is the type of horse that could just come out and do something that could surprise some people."

Werther's preparation hasn't been entirely straightforward since the injury either and includes a frightening incident last week when the quirky gelding dislodged his work rider and ran three laps of the small dirt track at Sha Tin.

"And going the wrong way around as well, we got very lucky that he wasn't injured again," Moore said.

Sam Clipperton will act as stand-in on Monday for fellow Australian Hugh Bowman, Werther's usual fly-in rider.

"It is a vote of confidence in not only Sam's ability but the way he has conducted himself since he arrived in Hong Kong," Moore said.

"One thing that has really impressed me about Sam is his communication and ability to give feedback. He has just been a delight to work with, he comes up to the trainers' stand each morning and he gives me his impressions.

"We also asked ourselves why we were flying a jockey in for a race after such stop-start prep when we've got a jockey here that can give you such great feedback ."

Werther was one of a record 26 Hong Kong-trained horses included in the World's Best Racehorse Rankings released this week.

Eight Hong Kong-trained horses made it into the top 50, three more than last year, while Maurice's dominant Longines Hong Kong Cup win was rated equal fifth-best performance of 2016.