Overall series leader Chad le Clos and Dutch flying machine Ranomi Kromowidjojo have enjoyed differing fortunes in the run-up to the Hong Kong leg of the FINA/airweave Swimming World Cup.

While the South African has been getting stuck into training with Commonwealth Games trials looming, Kromowidjojo — who finished the European cluster joint third in the women's standings with 122 points — has been in hospital for an operation.

“After the last leg of the World Cup I took a vacation, and I had my tonsils taken out about three weeks ago, so I’ve been less than two weeks back in the pool. I haven’t done much training so I’m not sure I’m in the same form as at the last cluster, but I’m really happy to be back in the pool and healthy — now I can speak again, eat again and swim again, so I'm really happy with that,” she told Friday’s press conference.

Le Clos bagged 159 points across Moscow, Berlin and Eindhoven, giving him a 66-point lead over Russian duo Kirill Prigoda and Vladimir Morozov.

He is entered in six races as the Hong Kong leg reverts to the previous version, from the maximum four that has been the norm elsewhere this year.

“It’s been a hard few weeks of training for me. I only got in late last night, so the travelling has been quite harsh. If I can get similar results to seven weeks ago, I’ll be very happy,” he said.

“This is my fourth time in Hong Kong and I’ve always had success here — long may that continue. I’ve put in a lot of hard training the last couple of weeks leading up to this, and the final cluster next month, and I have the Commonwealth Games next April, so I’m not having too much of a break this season — I'm going to push on and hopefully test some world records.

“I’m planning for the Commonwealth trials on December 16, so I'm in a hard block of training right now. Short course is definitely, physically, a lot easier for me to race. I think if it was long course right now, I’d be in a lot of trouble.

“I do enjoy the new format with four events, and at some legs you don’t have your main event. It’s good to change it up a bit and it makes it more fair. I enjoy it. Here we’re going back to the old format, six events, which is a little more difficult, but I’ll see how I go.”

Other star names on show this weekend include Sarah Sjostrom, Katinka Hosszu, the top two in the overall women’s table, and Prigoda, Morozov and Cameron Van Der Burgh, respectively joint second, and fifth, in the men’s standings.

Sjostrom set two world records at the last meet in Eindhoven. Those achievements propelled her to 266 points, with Hosszu — winner for the past five years — 90 points behind in second.

“We have a host of elite swimmers from around the world — Olympic champions, world champions — this week in Hong Kong. It gives us a good chance to have a close look at them, what they are really made of, and brings valuable experience to our local swimmers in preparation for next year’s Asian Games,” said David Chiu Chin Hung, Honorary Secretary of the Hong Kong Amateur Swimming Association.

This week, FINA announced an increase in prize money to US$600,000 across the top three men and women at the end of the series in November, with half of that going to the two winners. Previously, only the winners were going to be rewarded.

Prize money will also be extended to the top eight men and women at the remaining clusters, instead of six earlier.

Finals sessions start 1800 local time (0900 GMT) on Saturday and Sunday.