"This decision was not an easy one to make, and in no way is meant as disrespectful to the tour or 'sending a message' to anyone," Mickelson said in a statement. "I've talked for weeks about needing to find a balance between my game, my business affairs and my family, and now is the time for me to take some time off."

Mickelson was playing a corporate outing with sponsor Bearing Point in the Chicago area. He said he would be in Atlanta next week for the Tour Championship.

If all the best players are going to compete together in these PGA Tour Playoffs, it looks as though it won't happen until the fourth and final event next week at the Tour Championship.

Tiger Woods skipped the first week at The Barclays, saying his body and mind needed a break from back-to-back victories at a World Golf Championship and the PGA Tour Championship. Ernie Els and Scott Verplank skipped last week at the Deutsche Bank Championship.

Mickelson had planned to miss the third event, and winning in Boston while paired with Woods in the background gave him a platform to air some of his complaints. Without prompting, he mentioned on NBC Sports after his two-shot victory that he had made several suggestions to Finchem that were not acted upon.

Then, he refused to elaborate what those suggestions were.

"My frustration from this past year came from asking for a couple of things in the FedEx Cup that weren't done and not really feeling all that bad now if I happen to miss (an event)," Mickelson said Monday.

Mickelson's victory gave him the lead in the playoffs, although he could lose that if Woods were to finish second alone at Cog Hill this week, a course where he has won three times.

With the BMW Championship playing threesomes the first two rounds, Mickelson again would have been playing with Woods, along with Steve Stricker.

Mickelson wasn't the only player to withdraw. British Open champion Padraig Harrington also announced he was taking this week off, citing fatigue. Also missing among the top 70 eligible for the BMW Championship are Paul Goydos and Bernhard Langer, who has said he would not take part in the FedEx Cup, instead playing the Champions Tour and in Europe.