Wieber finished fourth during qualifying Sunday, but will miss a shot at Olympic gold because international rules only allow two competitors per country in the finals.
Teammates Aly Raisman and Gabby Douglas finished ahead of Wieber, leaving the 17-year-old on the outside of an all-around final at a major competition for the first time as an elite gymnast.
John Geddert, who has coached Wieber her entire career, called the rule ridiculous, saying it penalizes countries that have deep rosters.
"In this system it's a shame that the all-around champion doesn't get to compete on the finals at the Olympics because of a stupid rule of two per country," Geddert said.
The two-per-country rule has been in place in each of the last two games, designed to give gymnasts from lesser-known countries a chance to make it to finals. The top 24 individual finishers in Sunday's prelims made Thursday's final.
It's never been an issue for Wieber, who'd only lost two all-around competitions in the last three years, both of them to teammates. Until Sunday, she'd never missed an all-around final during her elite career.
Now, she'll miss out on the opportunity to follow in the footsteps of Mary Lou Retton, Carly Patterson and Nastia Liukin.
Wieber posted on her Facebook page Monday that it was "hard to explain these feelings."
Maybe, but it's hardly the first time an American has been shut out of the all-around finals despite having a score that would be more than good enough.
The U.S. placed five gymnasts in the top eight during qualifying at last fall's world championships, with only Wieber and Raisman moving on to the finals, where Wieber stunned Russia's Viktoria Komova to win the gold.
"It's the nature of the beast," said USA Gymnastics president Steve Penny. "It's an unfortunate reality."
Penny stressed Wieber will be "fine" in time for women's team finals, where she'll get a chance to bounce back as the U.S. pursues its first Olympic team gold since the "Magnificent Seven" in 1996.
The U.S. rolled through preliminaries on Sunday even with a series of miscues on floor. The scores are reset for the finals, and the Americans will also have to find a way to regroup after seeing their undisputed leader suffer the most painful setback of her career.
Wieber won't lack for opportunities at redemption, competing in three events during the finals. The only rotation she'll miss is balance beam, where a pair of uncharacteristic wobbles on Sunday helped open the door for Raisman.
Douglas is entered in all four events, buoyed by a surprisingly strong beam routine on Sunday. McKayla Maroney's injured right foot won't keep her from competing on vault — where she's world champion — and Kyla Ross will take her elegance to uneven bars and beam.
Raisman, the team captain, will work on beam and floor, where her typically steady performance on Sunday stunned her best friend and gave her an unlikely berth in the all-around finals.
Not that it will matter on Tuesday. The U.S. has been gunning for gold after a runner-up finish to China four years ago.
Geddert insists his star pupil will be ready.
"Team USA has work to do," Geddert wrote. "Jordyn will be instrumental in the team's chances to maximize their true potential as one of the greatest teams of all time."