The career of champion New Zealand galloper King Mufhasa might be winding down but a final overseas mission could yet reap another big reward.

The 10-time Group One winner has pleased connections as he prepares for Sunday's Champions Mile in Hong Kong, an event his owner has indicated is likely to be the horse's final race abroad.

Recent throat surgery has seemingly been a success and the eight-year-old will be out to wind back the clock in Sunday's Group One feature at Sha Tin.

"I haven't seen the horse look like this for years," co-owner David Archer told the Hong Kong Jockey Club after the gelding's trackwork on Friday.

"His muscle tone is back. He's rejuvenated."

King Mufhasa has done most of his racing in the care of trainer Stephen McKee before being transferred to Bruce Wallace early this year.

The gelding had a throat procedure after failing in the Chipping Norton Stakes in Sydney in March.

He showed the operation had been successful when he pushed star three-year-old Pierro to a neck in the Group One George Ryder Stakes last month.

"Everything about him is better since he had the operation to fix the epiglottic entrapment last month," Wallace said.

"His breathing is better, his action's better and he's done really well since he's been here in Hong Kong.

"I'd say he's in better shape than before his last run when it took the best three-year-old in Australia to beat him and my bloke was giving him weight."

King Mufhasa has won 20 of his 60 starts with eight Group One wins in New Zealand and another two in Australia.

Archer knows the gelding's career "is coming to an end".

"He'll have this run here in Hong Kong and maybe one or two more next season at home but that will be it," he said.

King Mufhasa will be ridden by Australian jockey Michael Rodd and faces eight rivals in the Champions Mile including a former stablemate, Glorious Days, who won his only start in New Zealand for McKee in 2011 before being sold to Hong Kong, joining the John Size stable.

Brett Prebble rides Packing Whiz while Sydney-based New Zealand jockey James McDonald is chasing back-to-back Champions Mile wins on Xtension.

Xtension is going for his third-straight win in the race having claimed the 2011 renewal when ridden by Darren Beadman.