Luke Donald can become world number one for the first time if he wins the Heritage event on the US Tour at Hilton Head, which starts on Thursday.
The 33-year-old Briton, who won the WGC Match Play in February, can leap to the top from his current third place.
Number one Martin Kaymer is absent this week and Lee Westwood, in second, is at the Asian Tour's Indonesian Masters, which has fewer ranking points.
Padraig Harrington and Sergio Garcia are in the European Tour's China Open.
Donald, who is paired with Australian Aaron Baddeley and American Mark Wilson for the first two rounds at the Harbour Town Golf Links, has only two members of the top-10 in opposition this week - world number five Graeme McDowell and American Matt Kuchar, who is 10th in the rankings.
McDowell has missed the cut in his last two tournaments, carding an 80 at the Arnold Palmer Invitational in late March and finishing three over at the Masters, two shots outside the cut mark.
The Northern Irishman lines up with Ernie Els and Briton Ian Poulter on Thursday and Friday.
Neither world number four Phil Mickelson nor sixth-ranked Tiger Woods have chosen to play this week.
Kaymer was not unduly concerned by the threat of losing the number one ranking he took from Westwood in February.
"It's important to be number one, but it's not the most important thing in my life," the 26-year-old German said.
"One day it will change and I will be two, three, five - hopefully it does not happen, but it's not something I am scared to lose and as long as I try 100% that's all I can do."
Westwood, who has won in Malaysia and Macau in the course of his 30 tournament victories, turns 38 on Sunday and said: "I like to play all over the world and consider myself a global player.
"I'm playing in Korea next week so it is good to start my Asian campaign this week. I like to play everywhere in the world if I can.
"I only got back from Orlando on Friday afternoon and I've been struggling with the 11-hour time change but I seem to have recovered from it."
Westwood finished 11th at the Masters after rounds of 72, 67, 74 and 70 left him at five under and he said: "I've been playing okay but I didn't have many great results. I played well in the Masters but didn't putt very well.
"I had other few decent results but nothing too spectacular. I'm looking to have that one week where everything comes together."
Thailand's Thongchai Jaidee, who has a record 13 Asian Tour wins and is one of Westwood's playing partners in the opening two rounds, is expected to provide the main challenge to the Englishman.