DUBLIN, Ohio (AP) -- Phil Mickelson hit the wall and then headed for the exit, withdrawing from the Memorial after a 79 on Thursday because of mental fatigue.
Mickelson said it was more important for him to be rested for the U.S. Open in two weeks than to finish Jack Nicklaus' tournament. He attributed the fatigue to playing three straight week, and then going to Europe to celebrate his wife's 40th birthday. He returned home to play a corporate outing Tuesday in New York, flew to Ohio for the pro-am and found his head wasn't in the game.
"The course here is in such great shape. It's a beautiful way to get ready for the U.S. Open," he said. "But I'm hitting it so poorly that ... I have to look at what's best for me to play in the U.S. Open, and I'm going to take the next few days to kind of rest up."
It's not unusual for players to withdraw after a high score -- it was Mickelson's worst in the 13 trips to the Memorial -- and three other players withdrew Thursday. But it's rare when the player is of Mickelson's stature, a four-time major champion inducted this month into the World Golf Hall of Fame.
Mickelson could not think of another time he withdrew without physical injury.
"I feel like it's the responsibility of a player to see through your commitment and finish the tournament and so forth," Mickelson said. "And I'm kind of overruling that just a touch, because I'm trying to think big picture on what's the best way for me to get ready for the Open."
The last time Mickelson withdrew was also at the Memorial in 2007, only then he had injured his wrist while practicing out of the rough at Oakmont for the U.S. Open, and he stopped after 11 holes. Mickelson wound up missing the cut at Oakmont.
Mickelson played Quail Hollow, The Players Championship and the Byron Nelson Championship, then headed to France and Italy with his wife, Amy.
"We had a great time, but I think I probably just went a little bit overboard last month, and it has nothing to do with playing poorly and so forth," he said. "But I do think I need to get rested to play my best for the Open."
Mickelson said he likely would see swing coach Butch Harmon to "get things straightened out," and go up to The Olympic Club in San Francisco to study the course. Mickelson has finished runner-up a record five times in his national open.
Whether it was more than fatigue, Mickelson wasn't saying.
His group, which included Masters champion Bubba Watson and Rickie Fowler, had a massive gallery with several fans taking pictures with their cellphones. Watson complained about the cellphones, though Mickelson said it was "more that mentally I wasn't able to focus as well from the last month."
Mickelson was even par for the tournament with a birdie on the par-5 11th, and then he played 7-over par the rest of the way, including a tee shot into the water on the par-3 16th for a double bogey.
"I knew he was struggling throughout the day," Fowler said. "You could tell he was a little tired. He's been traveling a bit lately. He told us there in the trailer when we were signing the cards. Obviously, it was a little bit of a grind out there today."
Watson said the phones have been "pretty bad ever since they made that rule" that allows fans to take phones on the course, although pictures are not allowed and there are designated areas to make calls.
"When they make these marquee pairings, more people are going to follow them and more people want to take pictures, so it makes it very difficult," Watson said. "Ever since they made that rule that cellphones are allowed, it's just not fun playing.
"It took Phil out of his game," Watson said. "Phil's a great player and a great champion, and it just took him out of his game. It's sad. It's sad that cellphones can make or break a championship."