Tournament host Woods (left) presents Singh with the World Challenge trophy
Tiger Woods admits he faces a struggle to rebuild his game and says he is still unsure when he will be able to play again following knee surgery.
Woods, 32, is recovering from anterior cruciate ligament surgery and has not played since his dramatic US Open victory at Torrey Pines in June.
"I've got to do a lot of work, and it'll be an arduous task," he said.
"I think I can handle a full swing now, but I'm not there yet. It's going to take a little bit of time."
The 14-time major champion, whose recovery is reportedly ahead of schedule, began hitting shots two weeks ago.
But asked how soon he would be able to make a full swing with his driver, Woods replied: "I don't know, it's just the recovery day-to-day.
"I don't know how my legs are going to start recovering, then swinging more full, progressing through the ball, and the ball count."
He is targeting the Masters in April as his first priority but he is likely to want to play competitively before then.
The WGC-Accenture Match Play Championship in Tucson in late February is a possibility for his much-anticipated comeback, although the WGC-CA Championship in Miami (12-15 March) is more likely.
In Woods's absence, Sergio Garcia and Padraig Harrington have narrowed the gap at the top of the world rankings.
Woods's lead has now shrunk from 11.3 to 3.8 points over world number two Garcia, who was nearly 15 points behind when he entered 2008 in 12th place.
But Open and USPGA champion Harrington, who has improved from eighth to fourth this year, could also have the American in his sights if he begins the 2009 season strongly.
Woods has been at the head of the rankings for a total of 529 weeks in his career. The last player to take the top spot from him was Vijay Singh in June 2005.
World number three Phil Mickelson, who was the subject of derogatory comments from Woods's caddie Steve Williams two weeks ago, has never been number one, but he may also have an opportunity to pass his long-time rival in the coming months.
Despite Harrington's heroics in the year's final two majors, Woods has been sorely missed in the game, not least by television viewers whose numbers have diminished.
"Tiger brings viewers in droves to the telecast so his absence had a negative impact," said PGA Tour commissioner Tim Finchem.
"You can also see some softness in tournaments where he typically plays in the galleries, but not significant.
"But I could write a script that, from the interest of competition, we are going to have a great year (in 2009). You guys (the media) are all going to participate in the coming back of Tiger, (speculating) can he play and can he have stamina."
Woods, though, is looking forward to spending the rest of the year at home in Florida with his wife Elin and their 18-month-old daughter Sam Alexis. Their second child is due in February.
"I'm just going to go home and celebrate Christmas with Sam and just kind of hang out at home," Woods told reporters after presenting Vijay Singh with the winner's trophy at his charity Chevron World Challenge event on Sunday.
"Then I will just gradually start building back into the game, but I'm really looking forward to it."