The school issued a statement Wednesday saying it declared the Heisman Trophy winner ineligible and that the NCAA agreed to reinstate Manziel after he sits out the first half against the underdog Owls.
"I am proud of the way both Coach Sumlin and Johnny handled this situation, with integrity and honesty," Texas A&M Chancellor John Sharp said in the statement. "We all take the Aggie Code of Honor very seriously and there is no evidence that either the university or Johnny violated that code."
The quarterback was being investigated by the NCAA for allegedly accepting money for signing autographs for memorabilia brokers, a violation of NCAA rules that could have led to a much longer suspension. ESPN first reported the allegations against Manziel earlier this month.
According to the statement, Texas A&M and the NCAA "confirmed there is no evidence Manziel received money in exchange for autographs based on currently available information and statements by Manziel."
Conditions for reinstatement include Manziel discussing his actions with teammates and A&M revising how it educates student-athletes about signing autographs.
"Student-athletes are often asked for autographs from fans, but unfortunately, some individuals' sole motivation in seeking an autograph is for resale," said Kevin Lennon, NCAA vice president of academic and membership affairs. "It is important that schools are cognizant and educate student-athletes about situations in which there is a strong likelihood that the autograph seeker plans to resell the items."
He likely will be replaced in the starting lineup by either junior Matt Joeckel or freshman Kenny Hill. Joeckel has thrown only 11 passes in his college career.
The news of Manziel's suspension was the talk of Twitter on Wednesday afternoon, with many questioning the length of the suspension. Former NFL and MLB star Deion Sanders was incredulous at the brevity of Manziel's suspension, after Dez Bryant was suspended for an entire season while at Oklahoma State after lying about having dinner with Sanders.
"Can we investigate the investigators? @DezBryant got suspended a season 4 lying about a dinner that wasnt a violation & Manziel gets a half," Sanders tweeted soon after the ruling was made public.
The decision also had a major impact in Las Vegas, where the odds of Manziel's chances of repeating as a Heisman winner and Texas A&M's chances of winning the national championship shifted dramatically on Wednesday. RJ Bell, the founder of sports betting web site Pregame.com, said that Manziel's chances of winning the Heisman jumped from 12-1 to 6-1 on Wednesday, and the team's shot at the title increased from 18-1 to 10-1.
The latest problem isn't the first time off-the-field trouble has put Manziel's career in jeopardy.
Manziel was arrested last summer after a bar fight near campus and charged with disorderly conduct, possession of the fake ID and failure to identify himself to police. It was an incident that put him in danger of being suspended from school and left him having to earn the starting job in fall camp.
Manziel admitted this June that he failed to identify himself to police following the altercation. As part of a plea deal, other charges against the 20-year-old, including disorderly conduct, were dismissed, and it looked like Manziel's trouble was behind him before the latest problems came to light.
Manziel became the first freshman to win the Heisman Trophy last season, setting numerous school and Southeastern Conference records while leading Texas A&M to an 11-2 mark and a victory over No. 1 Alabama in its first season in the SEC.
He followed that with a high-profile offseason of road trips to Las Vegas and the NBA Finals. Manziel got to meet Heat star LeBron James and rapper Drake, and he posted some Tweets that made headlines.
His biggest misstep, however, came during the summer when he departed early from a quarterback camp for high school players run by the Manning family in Louisiana. Manziel said it was a mutual decision after he overslept and missed meetings and activities.
Dat Nguyen, an All-America linebacker at Texas A&M in the 1990s and former assistant coach for the Aggies, lamented Manziel's mistakes, but noted what he's done for the program.
"I'm a little bit disappointed with what's going on down there," Nguyen said recently. "Going into the season I thought this would be the year for A&M to win a national championship and this has been a distraction. He made a bad decision and he's just got to move on … but overall the guy has put A&M back on the map."
Former Texas A&M coach R.C. Slocum, who is now a special adviser to Texas A&M's president, has watched Manziel's career with great interest and is looking forward to seeing how he'll follow up his incredible first season.
"This young man has been in a position that no one has ever been in," Slocum said on Wednesday before the suspension was announced. "He's been a freshman and a 20-year-old winner of the Heisman Trophy, and he's done some great things with that and he's had a few things I'm sure he'd like to have a do-over with. And if I were advising him, I might have said, 'That's probably not in your best interests to do that or say that or be there,' but in terms of the upcoming season, I'm as anxious as anybody to see what happens and see what the results are."
Manziel was the main attraction at SEC Media Days, where he was peppered with questions but answered with the same cool and calm he often shows in the face of a pass rush.
"I don't feel like I've done anything that's catastrophic," Manziel said at the time. "Of course, I've made my mistakes. It's time to grow up."
The day before the Aggies reported for preseason practice, ESPN reported Manziel signed thousands of autographs for brokers in Texas, Florida and Connecticut, and cited unidentified sources who said Manziel was paid thousands for dollars for the signatures.
Manziel has been off-limits to the media since news broke of the NCAA investigation, but has been practicing with the Aggies.
Top 25 schedule
No. 6 South Carolina vs. North Carolina, 4 p.m., ESPN
No. 24 Southern Cal at Hawaii, 9 p.m., CBS Sports
No. 1 Alabama vs. Virginia Tech at Atlanta, 3:30 p.m., ESPN
No. 2 Ohio St. vs. Buffalo, 10 a.m., ESPN2
No. 3 Oregon vs. Nicholls St., 2 p.m., FS1
No. 5 Georgia at No. 8 Clemson, 6 p.m., Ch. 4
No. 7 Texas A&M vs. Rice, 11 a.m., ESPN
No. 10 Florida vs. Toledo, 10:21 a.m.
No. 12 LSU vs. No. 20 TCU at Arlington, Texas, 7 p.m., ESPN
No. 13 Oklahoma St. vs. Mississippi St. at Houston, 1:30 p.m., Ch. 4 or ESPN2
No. 14 Notre Dame vs. Temple, 1:30 p.m., Ch. 5
No. 15 Texas vs. New Mexico St., 6 p.m.
No. 16 Oklahoma vs. Louisiana-Monroe, 5 p.m.
No. 17 Michigan vs. Cent. Michigan, 1:30 p.m.
No. 18 Nebraska vs. Wyoming, 6 p.m.
No. 19 Boise St. at Washington, 8 p.m., FS1
No. 21 UCLA vs. Nevada, 8 p.m.
No. 22 Northwestern at California, 8:30 p.m., ESPN2
No. 23 Wisconsin vs. UMass, 10 a.m.
No. 25 Oregon St. vs. E. Washington, 4 p.m.
No. 9 Louisville vs. Ohio, 1:30 p.m., ESPN
No. 11 Florida St. at Pittsburgh, 6 p.m., ESPN