Family comes first for Phil Mickelson.

The soon-to-be 47-year-old winner of five major titles is skipping this month's U.S. Open at Erin Hills in Wisconsin in order to attend his daughter's high school graduation.

“As I look back on life, this is a moment I’ll always cherish and be glad I was present,” Mickelson told Karen Crouse of The New York Times. “There’s no greater joy as a parent.”

Six times a runner-up at the U.S. Open, most recently in 2013, the tournament represents all that's standing in Mickelson's way of a majors Grand Slam. If he were to win the U.S. Open, he would become only the sixth and oldest golfer to complete the Grand Slam. Gene Sarazen, Ben Hogan, Gary Player, Jack Nicklaus and Tiger Woods are the quintet who have managed the lofty feat.

This was to be Mickelson's 27th U.S. Open tournament and he was feeling confident with the way his game was shaping up heading into it.

“The positive side is that the level of consistency day-in, day-out, the overall ball striking and just my overall level of play is consistently higher this year than it’s been in the last three or four,” Mickelson said. “About a stroke per round is what it comes down to.”

The 2013 British Open remains Mickelson's last tournament victory.

The 2017 U.S. Open gets underway on June 15.