Mickelson plays waiting game with new coach Harmon

CHARLOTTE, North Carolina (Reuters) - Three-times major winner Phil Mickelson is prepared to bide his time as he strives to improve driving accuracy with his new swing coach Butch Harmon.

Although Mickelson tied for third at last week's Byron Nelson Championship in his first tournament under Harmon's guidance, he does not want to rush any progress achieved.

"It's going to be a learning process," the American left-hander told reporters on Wednesday as he prepared for this week's Wachovia Championship.

"It's more than just a swing change. It's understanding what allows the ball to go straighter and so forth and how to do it. I'll take me a little time.

"Any time you make changes it does feel different and the key to being able to implement it and play well is getting a rhythm with it."

Mickelson, who worked with Rick Smith for most of his career before switching allegiance to Harmon nine days ago, is especially trying to eliminate his errant tee shot to the left, the wayward push or fade.

That blemish cost him a golden opportunity to win last year's U.S. Open at Winged Foot when his drive at the last bounced off the roof of a hospitality tent and into the crowd.

Mickelson then struck a tree with his second shot before running up a double-bogey six and handing the tournament to Australian Geoff Ogilvy.

Wounded by his Winged Foot experience, Mickelson has repeatedly said his main focus has been to "fix" his driving.

"The last piece that I really wanted to work on was driving the ball in the fairway, driving it straighter and not curving as much, being more consistent off the tee," the 36-year-old said.

"Slowly but surely it's improving. I'm excited about my play last week. I thought I started to hit the ball how I wanted to and I'm going to need that to carry over this week.

"This golf course is very challenging off the tee and I'm going to have to hit it very well."

The Wachovia Championship, the 19th stop on the 2007 PGA Tour, starts on Thursday.

(Writing by Mark Lamport-Stokes in Los Angeles)