Twenty-eight nations will battle for the title at Mission Hills in southern China in the $5.5 million strokeplay team event featuring the likes of Sergio Garcia and Asia’s first Major winner, Yang Yong-Eun.
Stenson, ranked seventh in the world, said the team format presented players with a different challenge from what they usually faced.
“I think it’s a whole lot of fun just to be able to play in a relaxed, but still competitive mode,” he said, adding that the field was stronger this year at Mission Hills.
“It feels like you could find the winners among 10, 12, 14 teams, something like that, most likely, and I guess there’s a few more teams involved than before, and some other countries are also stronger than they have been before.
“So it’s going to take some great playing to win.”
He added how much it meant to him to represent his native Sweden at the event.
“It’s also a great honour to play for your country, and I think that’s the most important thing — that we go out there and we represent Sweden,” he said.
Karlsson said Wednesday he had put his health problems behind him as he focuses on winning a second straight World Cup of Golf for his country.
Karlsson, who won last year’s World Cup at Mission Hills with his partner Henrik Stenson, topped the 2008 European Order of Merit but he has been forced to miss a large chunk of this season because of a persistent eye problem.
The Swede has slipped to 25 in the world rankings but comes into this tournament on a high after finishing runner-up at the Dunlop Phoenix in Japan on Sunday.
“I was out four months, from the last week of May until (September’s) Seve Trophy,” he said, adding that his eyesight was now returning to normal.
Karlsson said despite an extended break with his family in Sweden, he would rather have been out on the golf course.
“But it’s great now to be back and playing, and obviously coming into this event, felt great to play good last week. So (I’m) coming in here with a bit more confidence than before.”
“When I use both eyes now and read the lines and things like that, it works fine, no problem. But if I just look in one eye, there is a slight difference but I hope it’s going to keep improving,” Karlsson added.
“And I guess I will check it up regularly and sort of keep an eye on it — keep both eyes on it.”
As well as Sweden, other fancied teams include Ireland, England and last year’s runners-up Spain.
Other potentially strong challenges may come from Thailand, who feature Asian Tour regulars Thongchai Jaidee and Prayad Marksaeng, and India, who feature Jeev Milkha Singh and Jyoti Randhawa.
Of the 28 nations that tee off Thursday at Mission Hills, near Shenzhen, 18 will have qualified automatically via the world golf rankings. China will take their place in the field as the host nation alongside nine nations who have qualified through events held in Europe, Asia and South America.
The Omega Mission Hills World Cup is a 72-hole event with each team comprising two players.
The first and third days are fourball, in which four balls are used and the player with the fewest shots takes the hole for their team. The second and final days involve foursomes play, where the teams compete using only one ball per pair.