Playing in a threesome with Tiger Woods and Italian amateur Edoardo Molinari, Campbell shot a 77. Combined with his opening-round 75, that left him three shots off the cut of 9-over-par 149.
'That's life. You must carry on,' he said. 'There are a lot of U.S. Opens to go in my career, so I'm looking forward to that. I'll put this behind me.'
Campbell won at Pinehurst last year by shooting an even-par 280. In two rounds this year, he had 20 pars, 14 bogeys and two birdies.
He wasn't the only player to struggle on the difficult Winged Foot course; Woods also came in at 152.
'We just really struggled on the greens today,' Campbell said. 'The thing is, your play gets magnified worse out there. I didn't play that badly the last couple of days, just missed a few fairways. Once you do that, you have to chip out sideways and make bogeys.'
Campbell started on the 10th hole with a bogey, but got his only birdies of the tournament at Nos. 2 and 8 to complete the back nine at 1-over for the day. He then stumbled to four straight bogeys, effectively ending any chance of making the cut.
'The patience ran out toward the back nine there, where I missed a few fairways and made a few bogeys,' he said. 'I got frustrated, I think, and missed a few putts because of that.'
When it was over, Campbell accepted his fate with little more than a shrug of the shoulders.
'I can walk away. I'm just disappointed I'm not defending or doing well this weekend,' he said. 'It's one of the things that happened, and hopefully you just learn from it. This week was a lesson for me, and I need to go back and reflect on it and learn from it for next time.'
The last player to win the Open and then fail to make the cut the following year was Retief Goosen, in 2002.
Darren Clarke didn't sugarcoat it. After shooting a 72 on Friday, he vehemently complained about the greens at Winged Foot.
'The greens are poor, basically,' he said. 'They are poa greens, and they are very poor.'
Poa annua is considered by many to be nothing more than a weed. It's safe to assume that Clarke is among those with that opinion.
'They are jumping about, and with the combination of slope and the speed, it makes it very tough to hole putts on,' he said.
Asked if they are the worst greens he'd ever seen, Clarke responded, 'Yes. Comfortably.'
Clarke was in a dour mood after a round that he thought should have been a lot better.
'I made some very silly bogeys. Pathetic,' he said. 'Seventy-two is by far and away the worst score I could have shot, and I managed to do it.'
Clarke reached the midpoint of the tournament at 145, 6 off the lead.
Someone asked him what he needed to do to contend over the weekend.
'Just hole some putts, but I don't know how I'm going to do that.'
Jay Haas set a PGA Tour record Friday, making the cut for the 591st time during a career that began in 1976.
The 52-year-old Haas shot 72 for a 147 total, two under the cut line and breaking a tie with Tom Kite for most career cuts made.
Someone asked Haas if such a record means he's good -- or just old.
The answer: A little of both.
'Much more so that I've been out here a long time, and I've been good in spots and consistent,' he said. 'I've been healthy. I think that's a big part of it. But I guess I just hate missing cuts.'
Haas is 4-for-4 in making the cut at Winged Foot. He did it as an amateur in 1974, then as a pro in the U.S. Open in 1984 and in the PGA Championship in 1997.
DO WE REALLY NEED ALL 18 HOLES?
David Howell might want to stash an energy bar or two in his golf bag for the weekend. If the Englishman hadn't run out of steam at the end of his first two rounds, he could be leading the U.S. Open.
In Thursday's opener, Howell was cruising along at 4-under-par, thanks to a second straight birdie -- and his third in four holes -- at No. 14. Unfortunately, he then stumbled in with two bogeys and a double-bogey over the last four to finish with a 70.
Friday didn't go much better. Howell teed off from No. 10 and was 4-over for the day and the tournament when he reached the No. 6 tee. He then duplicated his finish of a day earlier, closing with two more bogeys and another double over the last four holes.
'Nothing I can say, really. I was going all right, and I just played poorly coming in,' he said.
David Toms withdrew from the tournament because of a back injury.
Toms told PGA officials of his decision less than two hours before he was scheduled to tee off in the second round at 1:03 p.m.
Toms said the injury happened on the 12th hole Thursday. He parred the hole but shot 9-over-par 79 that left him 10 shots behind first-round leader Colin Montgomerie.
Andrew Svoboda, a local golfer who has been playing Winged Foot since he was 10, shot 75 on Friday for a 150 total. He missed the cut by one. ... Tadd Fujikawa, at 15 the youngest person to play in the Open, will be headed back to Hawaii after following his opening 81 with a 77. He finished 140th in the 156-man field. ... Madalitso Muthiya, the first person from Zambia to play in the Open, finished at 81-80--161 and missed the cut by 12.