Pádraig Harrington, who has dropped three places to 61st in the latest world rankings following his finish in The Players Championship, has remained on in the US to compete in the Byron Nelson Championship in Texas this week.
Harrington added the Byron Nelson onto his schedule last year, where he finished tied-15th behind Jason Dufner.
Louis Oosthuizen will start as the top-ranked player but admits he would swap that to be in better form.
The 2010 Open champion will head up the field at the Four Seasons Resort in Irving but has not finished higher than 10th during the 2013 PGA Tour.
Oosthuizen said he will take confidence from being the top-ranked player but it counts for little if he does not perform.
“I think that’s what you make of it,” he said. “I think you probably take more confidence out of it, going into the event.
“I would rather come in a bit more in form than coming in top-ranked player.
“I felt like the last two tournaments I played I was getting better and I’m getting better results so hopefully the next three weeks something can happen for me.”