With the top 60 and ties qualifying for the final rounds at Erin Hills, the cut appeared set to fall at one or two over par as the afternoon wave started their second rounds.
Brian Harman stood on the podium with hands on hips, giving answers in the kind of matter-of-fact voice expected from someone used to the spotlight of a major championship. And I can hit those shots. I couldn't possibly shoot any higher than I did. "I just didn't get it in the hole fast enough".
McIlroy was never in the short grass from the 11th hole to the end on Thursday when he opened with a career-worst 78, and he didn't do almost enough in the second round until it was far too late.
It was the second straight year McIlroy missed the cut at the U.S. Open.
Paul Casey (-7) - After falling all the way down to 2 under for the tournament, Casey birdied five straight holes to fight his way towards the top of the leaderboard.
Charley Hoffman is all by himself on top of the U.S. Open - for now.
He became the third defending U.S. Open champion to miss the cut in the last six years, and has now missed the weekend in the last three majors.
Day admitted the course lay-out had played on his mind in both his rounds.
"Shooting a good score today gave me a lot of confidence", Matsuyama said. But I don't let it bother me. "I felt like I've been playing pretty well all week, and didn't have quite the numbers to show for it. It was a good round for me". You know, I've got four weeks off now.
"I think those two things and a lot of hard work, really". He'll head home to spend time with his son, River Jones Johnson, who was born Monday.
The 24-year-old's score is the lowest in relation to par in the history of the US Open, surpassing the eight-under 63 carded by Johnny Miller to win at Oakmont in 1973.
South Africa's Louis Oosthuizen had looked like being the early pacesetter, the former Open champion going to the turn in 32 and picking up shots on the 11th and 15th, only to run up a double bogey on the 17th.More news: Britain eyes Brexit deal 'like no other in history'
Fowler likes his chances of breaking his major duck on Sunday.
McIlroy meanwhile said a new putter being used for the tournament was not the problem. "These guys play a different game".
"I was a little anxious going out there", McIlroy said. Yeah, I'm hungry, but I'm not going to force it.
McIlroy has a hectic schedule again.
After the Travelers, McIlroy will take a week off and then play in the Irish Open, the Scottish Open and the British Open in consecutive weeks.
Kim won The Players Championship in May for his second PGA Tour title.
That's eight of the next 10 weeks after just seven starts in 2017.
His early exit was particularly perplexing because, Day said, "It's been the best preparation I've had going into a major in my career".
Casey swung and missed from the tall fescue on No. 3, and then chipped out and it rolled all the way off the green on the other side.
"My best friend has caddied for me for six or seven years", said Champ.
"There are always ups and downs out there, but I think with how long the course is and how long the days are, I'm sure I won't worry".
McIlroy followed an opening-round 78 with a 71 and is now a combined 43 over par in 18 U.S. Open rounds since winning the tournament at Congressional in 2011.