However, plenty of others were firmly in contention at the start of the penultimate day; only eight shots separated the leaders from those who made the cut on the bubble. Three players - Brian Harman, Tommy Fleetwood and Brooks Koepka - were in the clubhouse on five under, two back from Fowler.
The top three players in the world have never missed the cut in the same major dating to when the world ranking began in 1986.
After weeks of pouring his heart and soul into qualifying for the first U.S. Open played in Wisconsin, Madison's Steve Stricker was right where he wanted to be after the tournament's second round.
The Northern Irishman had a one-under-par 71 in his second round on Friday but was five over par overall after a disastrous 78 in the first round.
Justin Thomas landed a 3-wood on the 18th green where some players couldn't land a wedge, leaving him an 8-foot eagle putt that he calmly made for a 9-under 63 that matched one U.S. Open record and broke another.
Champ said a practice round with former British Open victor Louis Oosthuizen and four-times major victor McIlroy on Monday helped his confidence. Adam Hadwin tied a US Open record with six straight birdies. "Part of that is just age, and part I'll give credit to caddy Johnny McLaren, credit to my wife and my little boy".
McIlroy, as well as Day, will play the Travelers Championship near Hartford, Conn., next week as he gears up for the British Open.
"You can not play this golf course if you're not in position off the tee and I wasn't in position", McIlroy said.
"I wish I was about 5 shots better", Stricker said Friday at Erin Hills Golf Club. "But when you're visually looking down the fairway, I think when you're trying to aim at a target at a normal golf course, with normal width fairways, there's some pressure into hitting the fairway because it is a lot narrower than we have out here".
Despite having a huge power advantage over most of the field, and displaying excellent form with his irons, Koepka was unable to capitalise on a few good birdie chances.
"It's been an off-week for me with the putting", said the former world No.1, whose back nine of 40 included a double-bogey seven on the 18th.
"Just to see their games and how they play, I've grown up watching them".
Casey also dropped a shot on the 15th but regained his composure to birdied the 17th and 18th - the latter playing 676 yards - to get back to four under par.
QUOTEWORTHY: "I'm not here on the weekend, so it's unfortunate".
Kim won The Players Championship in May for his second PGA Tour title. And I can hit those shots.
However, with the overnight rain improving scoring conditions, Reed overcame some testing pin positions to card four birdies and a bogey on the front nine, before firing four birdies in five holes from the 12th.
But coming into Saturday, it wasn't hard to imagine that Spieth, sitting at even par, might be able to put together a run like numerous other younger players who ended up doing it.
Penguins, Predators each look to seize momentum in Game 5
Pekka Rinne was bad through the first two games and was certainly a big reason that Pittsburgh took an early series lead. After the third goal went by him to end the period, his night was over after allowing three goals on nine shots.
Justin Thomas shoots 63, trails Brian Harman by 1 at US Open
Open has been the one tournament fans relied on to watch the world's best golfers be roughed up and spat out like weekend duffers. And the prime beneficiary was Thomas, who catapulted up the leaderboard with his record-breaking nine-under-par 63.