I'm not just talking about his prodigious drives, though. "But you never really know until you put a card in your hand and you're under the gun little bit".
When he finished his round at Erin Hills, the four-times major victor was four shots outside the projected cut of one over.
McIlroy took four of them, including a near ace on the finishing par-three ninth, to finish the tournament on five under, which will miss the cut by two or three shots.
"You won't get a better day for scoring", Johnson said during the long walk to the scoring area, knowing he had wasted a prime chance in his bid to become the first back-to-back U.S. Open champion in 28 years.
Dustin Johnson had to gouge it out of the rough on at least eight occasions, including the par-5 14th hole when he tried to play conservatively and laid up into rough. I got out of position, but it's the attitude, it's the grit that matters at the end of the week. But I don't let it bother me. But I guess people don't like to read. "I'm not saying that this is the week or isn't the week, but I like the way this golf course suits me and we're off to a good start". The problem however was that it only lasted two holes. I'm looking forward to it very much.
Johnson, whose fiancée, Paulina Gretzky, had the couple's second child on Monday, said he would head home and work on his game over the coming weeks.
Day said he had the best preparation he's ever had heading into a major - even better than 22 months ago when, 70 miles away at Whistling Straits, he won the PGA Championship for his first major. He opened Thursday with a 9-over 81.
Shane Lowry looks like he will just make that cut after his two-over round of 74 on day two.
Hideki Matsuyama and Chez Reavie both shot the rounds of the day, posting seven-under 65s to move to five and four under respectively.
"Adam Scott wouldn't surprise me because he rebounded nicely from plus 4 to get back to even", Sherman said.
Next up is a weekend without most of the biggest names in golf.
He's twice been sidelined this year due to a rib injury, and had played just the Players Championship since the Masters. "I was a little anxious starting out yesterday and it caught up to me".
"I finally was able to close the deal this year at Valspar", Hadwin said after his round.
McIlroy has a hectic schedule again. You can not play this golf course if you're not in position off the tee, and I wasn't in position.
"I felt sick to my stomach", he said.
"I made the mistake of leaving it short and having it come back down to my feet", he said. "So I did a really good job of staying present, staying focused on the next shot".
Second-ranked Rory McIlroy also looked sure to have the weekend free when the Northern Irishman added a 71 to his first-round 78 for a five-over total of 149. He hit just five of 14 fairways for his round and ended six-over par, leaving him with a mountain to climb to make the cut on Friday. The rain leading into the start of the U.S. Open only softened the greens, and they already were slightly softer than usual because of the wind that could lead to unplayable conditions.