Stenson has Tiger in his sights at Volvo China Open
Henrik Stenson during the final round of the Masters at Augusta National on April 13, 2014 - by Rob Carr
The Swede, on the back of his historic exploits last season, is considered favourite at the $3.2 million event ahead of Jason Dufner, Ian Poulter and Chinese prodigy Guan Tianlang.
But the world number three will have to shake off the illness which has kept him in bed for the best part of two days and unable to practise at Shenzhen's Genzon Golf Club.
"I'm still waking up after some flu," a jaded-looking Stenson, 38, told reporters on Wednesday. "I'm feeling a bit weak.
"I spent the last 36 hours in bed. I haven't seen any of the golf course. I just need to rest up and try to make the best of the situation."
Stenson became the first player to win both the European Tour's Race to Dubai and US PGA Tour's FedEx Cup in a sensational finish to last year.
But he said his exertions left him low on energy and partly explained why he is yet to lift a trophy so far in 2014. He has only one top-10 finish and was tied for 14th at the Masters.
With Woods out after back surgery, he knows that now would be an excellent time to rediscover his form and leapfrog world number two Adam Scott to reach the top ranking.
"I'll never get a better chance than what I have now (to reach number one) but it will take some good golf," Stenson said.
Dufner is also looking to get back on a high by winning his first tournament since last year's PGA Championship, his first major victory after which he became a cult hero.
"This is the first time I've played in the China Open and I'm excited," said Dufner, who sparked the web craze of 'Dufnering' after being pictured sitting slouched against a wall.
"The golf course seems to be a good test. It's tight off the tee, which I like," added the American world number 17.
Ryder Cup star Poulter is no stranger to winning in China, having triumphed at the WGC-HSBC Champions at Mission Hills in Shenzhen two years ago.
Looking to lead the home charge is Guangzhou schoolboy Guan, who made waves at last year's Masters when he became the youngest player ever to make the cut, aged just 14 years and five months.
Guan is joined by 17-year-old Dou Zecheng, who last year became the youngest player to reach weekend play at the China Open, now in its 20th edition.
Others looking to impress at the 7,145-yard, par-72 Genzon course include 2011 China Open-winner Nicolas Colsaerts of Belgium and Italian Francesco Molinari.
Spaniard Pablo Larrazabal plays after an eventful Malaysian Open where he was forced to jump into a lake to escape a swarm of hornets who stung him on the face and head.
Australia's Brett Rumford would be the first player in the tournament's history to successfully defend the title if he wins come Sunday.