Key changes could go a long way for Zach Johnson, who is tied for 4th at CareerBuilder Challenge

Andrew Landry lost his PGA Tour card after missing the cut in half his 18 events in 2016 and had to regain his status on the Web.com Tour last year. He shot a seven-under-par 65 Friday in the second round of the CareerBuilder Challenge in La Quinta and holds a one-shot lead.

Jon Rahm, a 23-year-old who has rocketed to No. 3 in the world in only his second full season on tour, shot a 67 and is one shot back at 15 under.

Journeyman Jason Kokrak, who hasn’t won in his 163 starts on tour, is alone at 14 under after a 67.

And lurking one shot behind that after a 64 that included a stretch of five consecutive birdies sits Zach Johnson, a 41-year-old, 12-time winner on tour who has been trying to add to that total unsuccessfully since winning the British Open in 2015.

Simply put, Johnson says golf is fun now. He loves the new versions of clubs and ball he’s playing. “I’m hitting the ball farther than I ever have,” he said. “I mean, it’s crazy.”

And he’s been doing more work on physical conditioning and adopted a back-to-basics preparation routine that he believes will reap rewards.

“I know where my game can go,” Johnson said after his round on the PGA West’s Nicklaus Tournament Course, the same layout each of the others ahead of him played.

“I’m not saying I’m going to win five times this year, but I feel like the best part of my golf is still from this point on.”

Johnson had several meetings with his team in the offseason and ultimately decided that the intense practicing that he had been doing needed to be modified. Practicing efficiently was more important than practicing at length. The decisions didn’t necessarily come easily.

“The meetings were candid and frank,” he said. “And truth be told, I had to look myself in the mirror and ask for forgiveness for my stubbornness, for getting in the way. I mean you’ve been out here so long, my 15th year, you think you know everything, you’ve got it. But when I look at everything, I think I was probably doing too much.”

So rather than come to the desert and play each of the three courses used in this event, in addition to a practice round, he dialed way back. He played nine holes one day, nine another and worked on his short game.

“I went to La Quinta [Country Club] on Wednesday and chipped and putted for an hour and a half, I didn’t even look at the golf course,” he said.

Johnson, Kokrak, Rahm and Landry will all switch to the more difficult Stadium Course for Saturday’s third round, after which the field will be cut to the low 70 players and ties. Conditions were perfect for the first two rounds. Wind is expected for the third round, which could help create some movement on the leaderboard, particularly for those playing the Stadium Course.

Michael Kim, looking for his first win in his third season on tour, and Martin Piller, who earned PGA Tour status last year on the Web.com Tour, are tied with Johnson at 13 under.

The impacted leaderboard has 26 players within six shots of Landry and 51 players at eight under or better. One of those is not Phil Mickelson, who tacked a 68 on to his first-round 70 and is 10 shots off the lead. Those are scores that work well during a U.S. Open, but not in this event. Eight players shot 64 Friday; six more shot 65.

Mickelson, whose offseason training regimen has him looking fitter than ever and has produced biceps that wouldn’t be out of place on a strong side linebacker, is beginning his 2018 playing calendar with this event for the seventh straight year.

Last year, he was slowed at the start after two offseason hernia surgeries. He hasn’t won since 2013, he knows his iron play needs to improve, but he hasn’t lost his optimism.

“The scores obviously aren’t what I want, but it’s pretty close and I feel good about my game,” he said. “My driving has been above average. So if I continue to drive like this and get my iron game back, it’s going to be a good year.”