Fort Worth - Tiger Woods's world number one ranking is on the line again this week, but Phil Mickelson said his only chance of seizing the top spot is to put the matter out of his mind.
"It would be something very special," Mickelson said of the chance to gain the number one ranking for the first time in his career.
"But to accomplish that, I can't focus on that," said Mickelson, who could move atop the rankings with a victory. "I still need to go out and play like the number one player in the world."
Woods, the 14-time major champion whose life erupted in turmoil last November amid lurid revelations of marital infidelity, has rarely loosened his grip on the number one place he first claimed in 1997.
He has been ranked number one a total of 601 weeks, and his latest spell at the top has lasted 259 weeks.
David Duval and Vijay Singh are the only golfers to topple him - Duval for 15 weeks in 1999 and Singh five years later for 32 weeks.
But Woods' five-month break from golf as he dealt with the fall-out of personal scandal, and his struggles since his return, make him vulnerable.
After finishing tied for fourth at the Masters in his first start of 2010, Woods missed the cut at Quail Hollow in Charlotte and withdrew in the final round of the Players Championship with a neck injury. He is not entered this week.
"Tiger's performance and schedule are unpredictable at the moment," world number three Lee Westwood said at Wentworth last week. "Phil is a world-class player and has already won a major this year. The World Rankings are about consistency and number one and number two are more achievable than they have been in recent years."
But Mickelson, who has been ranked second in the world for a total of 244 weeks in his career, knows just how hard it is to take that last step up.
"It’s easier said than done," Mickelson said as he looked forward to the start of the Colonial on Thursday. "The only way to do it is to win here, and there is a very strong field.
"Fortunately it’s on a golf course that I have played well on in the past and that I enjoy. I’m looking forward to that challenge and that opportunity to overtake the top spot."
Mickelson's return to Colonial figures to be an emotional one.
He won here in 2008 but didn't defend his title last year as he stayed home to be with his wife, Amy, shortly after she was diagnosed with breast cancer.
Tournament players and staff held a "Pink Out" during the third round last year, wearing pink to raise awareness of breast cancer and send a message of support to the Mickelsons.
"They were out their defending champion, and yet they went out of their way to show one of the nicest gestures I've seen," Mickelson said. "Last week, Amy and I commiserated over our one-year anniversary and this event really helped us get through some tough times.
"It meant a lot to us and gave us a huge emotional boost at a very difficult time for us," he said.
While Mickelson has been the feature attraction, Steve Stricker is the defending champion.
Stricker will be playing his first tournament in six weeks. He was sidelined after the Masters with a chest injury for which doctors recommended rest and rehabilitation.
"There is still some tightness or stiffness to it, a twinge here and there. But it was going to be a hard decision to stay home this week and give it another week of rest," Stricker said.
"I don't know if it's totally healed yet, but I'm swinging without any pain."
Stricker said it was natural that attention would be focused on Mickelson.
"He is almost the defending champion as well this week," Stricker said. "I thought it was the greatest feel-good story in golf when he won at the Masters, and seeing Amy there.
"I think he is going to be tough to beat here, too. I think he will be coming back here with his game in shape and winning here a couple of years ago, obviously he's got some good vibes, too."