Harrington is a three-time major winner
Padraig Harrington has set himself the ambitious target of winning his next three events to stay in the hunt for the inaugural Race to Dubai.
The three-time major winner, who has won only once this year, plays in the Singapore Open, starting on Thursday.
The Race to Dubai spans 50 events, with the winner pocketing $1.5m (£916,000) and the top 60 making the Dubai World Championship in November.
"It's mathematically possible I can make number one," said the Irishman.
"I would need a big run and that means I would have to win two of my last three events and finish very high up in the other.
"So if I am going to aim for that I may as well try and win all three. It is possible but it's a very long shot."
Harrington, the 2006 European Tour Order of Merit winner, won the Irish PGA Championship prior to finishing 65th in The Open at Turnberry, but his last top-level success was the US PGA Championship in August 2008.
Harrington spent the first six months of this season remodelling his swing and has recently reaped the rewards with seven top 10 finishes in eight events since The Open.
"I have had two halves to my season. The first six months performance-wise wasn't very good, I was doing a lot of work on my game," said the 38-year-old world number six.
"I have now played well over the last three months but haven't got a win. It's nice to be playing well, but it's getting frustrating not to win.
"A win is going to happen, but it gets harder when you try to push it and force it. I have got myself in positions, but now I need to just let it happen.
I have won tournaments every year since I turned pro. I'm running out of time
"I am anxious to win, but that's not helping, I need to take it easier on myself.
"There is nothing I can do any different. If I keep doing the things I have for the last couple of weeks, I will surely get a win."
Despite finishing third at the Portugal Masters, Harrington slipped out of the top 15 of the Race to Dubai and sits 16th.
But with winner's cheques totalling more than £1.8m to play for over his next three events in Singapore, Shanghai and Dubai, Harrington can still catch current leader Lee Westwood, who is playing in this week's Volvo World Match Play in Spain.
Last year in Singapore, Harrington was in contention for the title down the stretch, but missed out by a stroke after hitting into the water on the 16th.
"It would be nice to go one better than last year. I came very close but it wasn't to be," said Harrington.
"It's a slightly different course this year, but hopefully I will be there or thereabouts on Sunday.
"My game has been in good shape. I have been struggling a bit with my posture and I am fighting a bit of a cut so hopefully that won't be there."
Harrington and South Africa's Ernie Els, who both tied for second at last year's tournament, face stiff competition from world number two Phil Mickelson at the Sentosa Golf Club.
Els, who missed a putt at the 18th hole last year that would have forced a play-off with winner Jeev Milkha Singh, is looking for his first win of the year.
"I still have nightmares about the birdie putt that I missed on 18," the South African said. "I have won tournaments every year since I turned pro. I'm running out of time."
Els complained that this week's World Match Play Championship forced players to choose between the two events.
"I don't quite understand that," said the three-time major winner. "We've got more controversy this week."
The Race to Dubai top four of Westwood, Martin Kaymer, Rory McIlroy and Paul Casey are all scheduled to play in Spain.