LOS ANGELES — The phone call, one that Butch Harmon had been hoping would come, came in November. 

Rickie Fowler was on the line. 

“Butch, I’m lost,’’ Fowler told Harmon. “I need help. I don’t know what to do.’’ 

Harmon, the legendary 79-year-old swing coach, who helped shape the careers of Tiger Woods and Phil Mickelson, among others, had coached Fowler previously before the golfer made a switch to John Tillery, a professional marriage that didn’t work. 

Fowler’s world ranking, which had been as high as No. 4 in 2014, when he finished in the top five at all four majors, had tumbled to a low of 173rd last summer.

After he was once a fixture in major championships and a consistent contender, Fowler’s world ranking not only had sucked the life and confidence out of him but also was excluding him from those major fields. 

He entered the US Open this week at Los Angeles Country Club having played in just four majors in the past three years.

His last US Open and Masters appearances were in 2020. 

Now, Fowler will wake up on Saturday morning with the 36-hole US Open lead at 10-under.

He leads Wyndham Clark (9-under) by one shot, Rory McIlroy and Xander Schauffele (8-under) by two, Harris English (7-under) by three and Dustin Johnson and Min Woo Lee (6-under) by four. 

Fowler’s 36-hole total of 130 tied the US Open record for lowest score and his 18 birdies in 36 holes set a US Open record. 

Since 2010, Fowler has 12 top-10 finishes in major championships, the most of any player who hasn’t won one.

Because he had been lost in the wilderness the past few years, though, the thought of a top-10 in a major seemed preposterous.

After all, you’ve got to be in them to win them, or even contend, right? 

That is where Harmon, watching from afar, felt Fowler’s angst. 

“Some guys have got to hit rock bottom,’’ Harmon told The Post over the phone Friday. “Rickie went beyond rock bottom. It pained me to watch him. I love him as a friend. And, as I watched him struggle, I was wishing he’d pick up the phone and call me.’’ 

Harmon’s style has never been to force himself — or his services — on players.

If they want help, he wants them to come to him. It’s not arrogance, but more respectfulness.

He never has been one of those coaches to advertise his services. 

“Finally,’’ Harmon recalled, “he called.’’ 

It might turn out to be the most important call Fowler ever made. If he’s able to convert his 36-hole lead into his first career major championship victory, it’ll be hard to argue that it wasn’t. 

“He was so lost,’’ Harmon recalled. “He had no idea what he was doing.’’ 

Harmon helped reconstruct not only Fowler’s swing, but also, and more importantly, his psyche. 

“I feel like he’s a very good golf and life coach,’’ Fowler said Thursday after his opening round. 

“I have mental talks with him all the time,’’ Harmon said. “I am a really positive person. He’s come from a dark place in golf and I’m not going to take him back there.’’ 

After his gritty 2-under 68 on Friday, Fowler reflected on the dark times. 

“I sure hope everyone can relate to struggles because everyone deals with them,’’ he said. “No one’s perfect. I think you’d be lying if you haven’t been through a tough time, especially if you play golf. Going through the last few years, yeah, there’s probably plenty of people that might have just hung it up. 

“I wouldn’t say I enjoyed it, but looking [back], I did, just because of how much I learned about myself, my swing, my game. I wouldn’t be in this position had I not gone through the last few years. I’m looking forward to the weekend. It’s been a while since I’ve felt this good in a tournament, let alone a major. It’s going to be a challenge, but I’m definitely looking forward to it.’’ 

Harmon, who’s based in Las Vegas and doesn’t travel as often as he used to (he no longer goes to tournaments other than the Masters), said now when he watches Fowler on TV he likes what he sees in his body language. 

“The tip-off is he’s got that little step back,’’ Harmon said. “You can see he’s happy again. He’s in a good place mentally. You can see that energy in his body that he’d lost when he was struggling. He’s back. He’s going to win. The game needs him to win.’’ 

Harmon said he spoke with Fowler after his opening-round 62, which set a U.S. Open record for lowest score ever, and said, “There was nothing to talk about with the swing.’’ 

“It’ll be interesting to see what he shoots [Friday], because it’s hard to follow a 62,’’ Harmon, who spoke to The Post before Fowler teed off, went on. “But I expect him to shoot a good round.’’ 

He did. 

And here we are. 

Thanks to perhaps the most important phone call of Fowler’s life.