Mickelson wasn't at "Hogan's Alley" to defend his title last May after finding out that his wife had breast cancer, yet they were in everyone's thoughts. The tournament held a "Pink Out" during the third round to honor Amy Mickelson and raise awareness of the disease.
"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 Wednesday. "So there is certainly an emotional loyalty on my part toward Colonial."
When Mickelson won the Masters Tournament last month, his wife was behind the 18th green with their three children to share in the victory. That is the only time Amy Mickelson has been at a golf course since her diagnosis last year.
Amy Mickelson will not be at Colonial this week, when most players and tournament officials are expected to wear pink for another "Pink Out" on Saturday.
"Last week, Amy and I commiserated over our one-year anniversary and this event really helped us get through some tough times," Mickelson said. "It meant a lot to us and gave us a huge emotional boost at a very difficult time for us. We will always remember that and be appreciative of that."
With Mickelson, defending champion Steve Stricker, Jim Furyk, Ian Poulter and Paul Casey in the field, the Colonial boasts five of the top eight players in the world.
The two area players in the field are Swainsboro, Ga., resident Blake Adams and former Louisville, Ga., resident Brian Gay, who shared second place in last week's Byron Nelson Championship.
Mickelson has a chance to overtake Tiger Woods and grab the top spot in the world rankings for the first time in his career if he wins his third championship plaid jacket at the Colonial.
"It would be something very special. But to accomplish that, I can't focus on that," he said. "I still need to go out and play like the No. 1 player in the world."