For world number 18 Morikawa, the US Open will be his first start since he withdrew ahead of his final round at the Memorial nine days ago when he was two shots off the lead.

As a result, Morikawa said he will need to squat down to put his tee in the ground at Los Angeles Country Club but that he is otherwise swinging fine going into the year's third major.

"There's no pain swinging right now, which is great," Morikawa said on Tuesday. "I might be teeing up kind of weirdly this week, so don't take too much into that, but it's just precautionary."

Morikawa, whose major wins came at the 2021 British Open and 2020 PGA Championship, said that despite the back issue he has not had to make any other changes to his routines and that he has hit out of bunkers and rough pain-free.

The American also said the back injury that derailed his Memorial hopes had nothing to do with golf but rather from exercises he was doing in the gym between rounds.

"It sucked, because I felt like I was grinding for three days to put myself in contention. We figured some things out Saturday afternoon," said Morikawa.

"That's when you're excited to wake up and you're like, man, we can put together a few birdies early on and you're right there tied for the lead. Who knows what could have happened, but it's very unfortunate. It sucked."

Morikawa, a five-time winner on the PGA Tour with four top-10 finishes this season, will play the first two rounds this week alongside world number one Scottie Scheffler and No. 7 Max Homa.