Phil Mickelson has pledged to give "everything I have" when he bids to complete the career grand slam in his home city of San Diego on the back of his stunning US PGA Championship triumph.
Just nine days before rolling back the years at Kiawah Island to become golf’s oldest major champion, Mickelson had reluctantly accepted a special exemption for June’s US Open at Torrey Pines, where he will turn 51 the day before play gets under way.
That exemption was required because Mickelson had slipped out of the world's top 100 and the prospect of him joining Gene Sarazen, Ben Hogan, Gary Player, Jack Nicklaus and Tiger Woods in having won all four majors looked increasingly far-fetched.
But as well as giving Mickelson a sixth major title — to match the totals of Sir Nick Faldo and Lee Trevino — Sunday's victory also came with a five-year exemption for the US Open, an event in which he has finished runner-up a record six times.
“If I’m being realistic, it’s very possible that this is the last tournament I ever win,” admitted Mickelson, who won twice on the Champions Tour last year but had failed to record a top-20 finish on the PGA Tour until Kiawah.
“But it’s also very possible that I may have had a little bit of a breakthrough in some of my focus and maybe I go on a little bit of a run, I don’t know.
“I’ve believed for some time now, without success, that I could play at my best and compete in major championships still, but, until this week, I haven’t proven it to myself or anyone else.
“But I do believe that if I stay sharp mentally I can play well at Torrey Pines.
“I’ll take two weeks off before that and go out to Torrey and spend time on the greens and really try to be sharp for that week because I know that I’m playing well and this could very well be my last really good opportunity — although I get five more — to win a US Open.
“So I’m going to put everything I have into it.”
Mickelson's most recent second place in the US Open was behind Justin Rose at Merion in 2013, a month before he won the Open Championship at Muirfield.
But he has never threatened to complete the career grand slam and even skipped the 2017 US Open — at an Erin Hills venue which was expected to suit his game — to attend his daughter’s high school graduation.
Worse was to come the following year when Mickelson made the headlines for all the wrong reasons at a brutally difficult Shinnecock Hills.
Already four over par for the day during the third round on his 48th birthday, Mickelson badly overhit a putt on the 13th green which was set to roll off the putting surface.
Mickelson had other ideas and prevented that from happening by running after the ball and hitting it while it was still rolling, a flagrant breach of rule 14-5 which incurs a two-shot penalty.
Initially unrepentant, Mickelson told the numerous critics — including fellow professionals — who felt he should have been disqualified to “toughen up”, but later admitted he was “embarrassed and disappointed” by his actions.
“It was clearly not my finest moment and I’m sorry,” Mickelson said.
Whether his finest moment is still to come remains to be seen, but it will not be for the lack of effort.
“Worked harder, is the deal,” Mickelson said when asked to explain his longevity.
“I just had to work harder physically to be able to practice as long as I wanted to and I’ve had to work a lot harder to be able to maintain focus throughout a round. That’s been the biggest challenge of late.
“My desire to play is the same. I’ve never been driven by exterior things. I’ve always been intrinsically motivated because I love to compete, I love playing the game.
“I love having opportunities to play against the best at the highest level. That’s what drives me, and I think the belief that I could still do it inspired me to work harder. I just didn’t see why it couldn’t be done. It just took a little bit more effort.”