The HSBC Champions event in China has lost some of its draw after the world's two top-ranked players, Rory McIlroy and Tiger Woods - withdrew from the event.

While their absence gives other golfers in the field an opportunity to close the gap on the money lists, the tournament's sponsors are disappointed that the game's two biggest names are absent from the star-studded field.

Global head of sponsorship and events for HSBC Giles Morgan was particularly upset that McIlroy skipped the event after playing elsewhere in Asia.

"To have a World Golf Championship in Asia is really important for the sport, to balance the sport out, and to grow," Morgan said.

"And because it's a World Golf Championship event, it requires the best players to be here."

Instead of competing at the hilly Mission Hills course, Woods is making a trip to Singapore for corporate commitments, while McIlroy is watching tennis in Bulgaria where his girlfriend - Caroline Wozniacki - competes in the WTA's Tournament of Champions.

The Ulsterman, however, is scheduled to play in the Barclays Singapore Open next weekend, as well as the Hong Kong Open the following weekend.

"I think the feeling is - and it seems to be among media and a lot of other people with the stakeholders, not just us as the sponsors - well, if they're in China and there's a World Golf Championship, this would be a good event to be at because it's a WGC, but a WGC in Asia, which helps elevate the game," said Morgan, who added that both players did apologise to him personally for missing the event.

Four-time major winner Ernie Els was also disappointed that the pair was missing.

"You know, you can't play every week. You can't play everywhere," the reigning British Open champion said.

Golf 365