BROOKLINE, Mass. — Midway through the U.S. Open, Collin Morikawa stood atop the leaderboard looking to add a third major championship to his résumé.But on moving day, as Saturdays are called on the PGA Tour, Morikawa uncharacteristically went backward. After a seven-over-par 77, Morikawa found himself six shots off the pace when he teed off on Sunday. It proved to be too great a deficit to overcome to move back into contention, but he walked off the course at the Country Club more than satisfied, having improved his score by 11 shots from the previous round.“I don’t know if I found something,” he said after his 66 moved him to two under par and into a tie for fifth. “I think it just taught me that I need to go play golf. This year has been so focused on trying to hit that cut and trying to be so perfect, and that’s who I am. But just go out and play. Things are going to be tough. The ball is not going to go where you want. But just figure it out.”Morikawa, the defending British Open champion and the 2020 P.G.A. Championship winner, played a bogey-free back nine in dank, cool conditions. He came to the 18th green figuring he needed to make a birdie to have any chance. But his putt came up a foot short.“I had some momentum, kind of carrying on,” said Morikawa, who shot a 32, three under par, on the back nine. “If I could have gotten to four, that would be a nice number to post. It was still a few short, but it was a much-needed round.”Morikawa shot 66 on Friday, emerging as a co-leader, with Joel Dahmen, after two rounds. Then came the disaster on Saturday, when his round featured four bogeys, two double-bogeys and just one birdie.He had said before the tournament that he was struggling with his iron play. He normally plays a left-to-right cut shot, but lately the ball had been going right-to-left, he said. But Morikawa had little trouble the first two days.“With the way I had been playing, I did not see that coming,” he said. He added: “I hope many seven-overs aren’t coming in the future. But it just kind of made me refocus and kind of just get back into things. Just get it off the tee, onto the fairway, and then worry about it from there.”Morikawa called Sunday’s round “a huge boost” and said he would remember the weekend more for his three sub-70 scores than the Saturday meltdown. Before the third round, his worst score in a U.S. Open had come in 2020 at Winged Foot in New York, where he opened with a 76 and missed the cut.Last year, he finished in a tie for fourth at Torrey Pines near San Diego. He then went on to win his second major, besting Jordan Spieth by two strokes at Royal St. George’s.As was the case last year, Morikawa said he planned to play the Scottish Open to tune up for this year’s British Open at St. Andrews, a course he said he had not yet played. But he said he understood it would be a lot different for him this time around for two reasons: his status as the reigning champion and the venue, the historic Old Course.“I think I’m going to have to do a really good job prioritizing every single day and splitting up what I need to focus on,” he said. “Whether it’s the golf or whether I just need to enjoy just being there at St. Andrews, back as the defending champion.”He added, “There’s going to be a couple more distractions, but that doesn’t mean I won’t be focusing on golf when the time comes.”This was Morikawa’s 14th official tour event of the season. He tied for second at the Genesis Invitational in February and placed second at the CJ Cup at Summit in the fall. He finished fifth at the Masters Tournament, closing in style by holing out from the bunker on the 72nd hole.In addition to his two majors, Morikawa has three other PGA Tour victories, all coming before he turned 25. He won twice last season; the World Golf Championships and the British Open. He also won the DP World Championship in 2021. Entering the U.S. Open, he was ranked No. 7 in the Official World Golf Rankings and was 20th in points on the FedEx Cup list.In addition to the golf events Morikawa has planned, there also is a wedding coming up to his longtime girlfriend, Katherine Zhu. Unlike Brooks Koepka, who publicized his June wedding, Morikawa would not divulge any plans of the impending nuptials.