Luke Donald says regaining world number one spot is secondary to retaining his BMW PGA Championship title.
Donald topped the rankings for the first time by winning the same event last year and stayed there until Rory McIlroy supplanted him in March.
"It's a privilege to be world number one. Getting there was a lot of work and it's something I will tell my grandchildren about," said Donald.
"But the main goal is to go out and try to defend my title."
Donald beat then world number one Lee Westwood in a play-off last year and his countryman will also be at the European Tour's flagship event, along with McIlroy.
Chicago-based Donald briefly regained his number one spot from the Northern Irishman with victory in New Orleans in April, but the 23-year-old has been top of the pile again since Wells Fargo earlier this month.
And McIlroy, who will next month defend his US Open crown in San Francisco, is in bullish mood at Wentworth.
"You have to believe you're better than anyone else," he said.
"On my day I believe I can beat anyone in the world. It's just a matter of going out there and showing everyone else what I believe."
If Donald finishes second this week, McIlroy would have to win to keep hold of the number one position and if McIlroy misses the halfway cut - as he did on his last start at the Players Championship two weeks ago - Donald would only need to finish eighth or better to overtake him.
"The victory is at the forefront of my mind," said Donald, who has been awarded honorary life membership of the European Tour in recognition of his record-breaking 2011 season.
"There has been a lot of jostling back and forward between Rory and myself over the last six months or so.
"But it's been fun for us - added motivation I suppose to get to that number one spot."
Westwood saw his chances disappear at the 18th hole in the play-off 12 months ago when his approached rolled into the water.
"It should not have gone to a play-off," said the world number three, who is without his regular caddie Billy Foster this year because of a long-term injury.
"I three-putted the 16th in the last round, didn't birdie the 17th going in with a three-iron and then missed a five-footer for birdie at the last.
"I had my chances. It was my own fault."
Meanwhile, Scotland's top golfer Martin Laird, ranked number 31 in the world, makes his debut at Wentworth.
"Hopefully I play well enough to make that Ryder Cup team and then at the end of the year I'll evaluate and see what I want to do next year," said Laird.