If Phil Mickelson still leads the 99th U.S. Open on Sunday, every eye in the gallery will be on him. And every ear, too. Never will so many fans, as well as his rivals, be listening so hard for the sound of a beeper.

In his caddie's bag, Mickelson has placed a beeper so his wife, Amy, can notify him if she goes into labor. Their daughter, to be named Amanda, isn't due until the end of the month, but, as the expectant dad says, "With labor you just never know."

What would Mickelson do if that beeper blared? "I don't care if it interrupts a swing," he said Thursday after shooting a 67 to tie with three others for the Open lead. "I'm getting a car as soon as I can and getting to the airport."

Phil, would you say, "Sorry, gotta go," if you were leading on Sunday?

"Yes."

What if you were on the 18th green with a putt to win?

"Five minutes [more or less]? Okay," said Mickelson, conceding he would putt out for golf's top prize. "But I want to be there for the whole process."

The D-Day invasion was haphazard compared to Operation Amanda.

"It'll take about five hours and 15 minutes from the time I get the beep until I arrive at the hospital [in Phoenix]," said Mickelson. "I've got a plane standing by. As you know, I'm a pilot. I've got my copilot ready to fly."

Comedy is full of stories about addled husbands driving crazily to the hospital. Would Mickelson fly the plane? "Possibly," he deadpanned.

Though the odds are against it, don't we have to root for the beep? Would dapper Phil, pink collar up, really bolt the Open for a baby? It wouldn't just be sports history. It would be social history. Someday, he might carry the Arizona senatorial seat just on the women's vote alone.

Would a jockey hop off his horse in the post parade at the Kentucky Derby to grab a taxi to the hospital? Would a Super Bowl quarterback say, "Family first," before the coin toss? Remember, this isn't just some lineman skipping a midseason NFL game. This is a chance for a 29-year-old star who has never won a major title to solidify his status at storied Pinehurst.

Cynics say that with his shaky history in the majors, if Mickelson is in the lead on Sunday, he's more likely to go into labor than his wife.

Maybe it's more likely that impending fatherhood may actually be good for Mickelson. Only three players won 10 tour tournaments at a younger age than Mickelson -- Jack Nicklaus, Gene Sarazen and Horton Smith. Yet the majors haven't been kind to him. He's 56 over par in 22 rounds in the Open as a pro and never finished in the top three. "Now I have something to take my mind off a major championship," said Mickelson.

The southpaw may have built up the quick-exodus scenario in his own mind as a way to deflate the pressure. He's thought of everything, that's for sure: "We've got a little code in case somebody gets a wrong number and beeps us accidentally. So, if she punches in the code, I'm getting out."

What a difference a generation or two makes. Would Ben Hogan, Sam Snead or Arnold Palmer have passed up a shot at a green coat or a national championship to share in the transcendent joys of childbirth? It's hard to picture. Byron Nelson, a sensitive male ahead of his time, might have.

Even within Mickelson's own generation, some might not make the same choice. No. 1-ranked David Duval, who's also tied for the lead, was asked what he'd do. Duval, who isn't married, ducked any answer. Yet nothing stopped him from a simple, "Yes." Clearly, he'd have to do some thinking. Not Mickelson, who makes Alan Alda look insensitive.

"When I was 20 years old I thought that, gosh, the majors would be so important I didn't really know how I would feel," said Mickelson. "We're very fortunate to be able to have a child. We thought we were going to have [fertility] problems, but it came very easily. This is something I don't want to miss. It's a once-in-a-lifetime opportunity to be there, whereas the U.S. Open takes place every year."

Clearly, Mickelson's choice is so entirely personal that there's no right or wrong decision. It's just his decision. But that doesn't make it any less fascinating. If you were a lawyer with one chance to argue before the Supreme Court or a musician with a chance to play Carnegie Hall, what would you do? Perhaps the deciding factor for some of us would be the thought: What if something went wrong? How could you not be there?

Others besides Mickelson face decisions. Jim (Bones) MacKay, the caddie, has a fat payday riding on Mickelson. What if that beeper goes off on the 16th hole but Phil doesn't hear it? Should Bones conveniently forget?

The person most tempted not to tell Mickelson may be Amy Mickelson. She knows how much of her husband's reputation and place in sports history hinge on a handful of weeks such as this. To his credit, Mickelson has made it absolutely clear to his wife that he's not just talking the talk.

"I made it clear, and she understands, that I want to be there off the bat and that I don't want to miss it," said Mickelson. "This is the most important thing as far as our family is concerned. I would be very disappointed if she were to go into labor and not call me."

For Mickelson, these next three days will be a double-edged sword. Will the nerves of fatherhood and the nerves of the U.S. Open combine to frazzle him? Or will thinking of Amy and Amanda calm him? How bad is a bogey if you're havin' a baby?

In 1963, Jack Nicklaus's son, Steve, was born four days after The Masters. Nicklaus was famous for fainting at the birth of all five of his children. Eventually, a friend was assigned to stand behind him just to catch him when he fell. So, he must have had the daddy jitters.

Yet he won that Masters by a shot. Now that's what you call an omen.

CAPTION: Phil Mickelson, playing with a beeper in his bag to alert him when his wife goes into labor with their first child, is a first-round co-leader.