- Witnesses tell school officials Winston yelled vulgar phrase on campus
- Source: Punishment increased to full-game suspension after Winston's story didn't match
- Winston apologized: "I can't carry myself that way"
Florida State quarterback Jameis Winston missed all of Saturday night's marquee game against Clemson --- not just one half as previously announced -- because of a vulgar comment witnesses said he made on campus this week, the school said.
FSU, the nation's top-ranked team, struggled early but outlasted Clemson to win 23-17 in overtime.
FSU initially said the Heisman Trophy-winning quarterback would miss the first half of the Seminoles' game in Tallahassee, after people reported seeing him yelling an sexually explicit phrase near the FSU student union on Tuesday.
But FSU Athletics Director Stan Wilcox increased the sophomore's punishment late Friday after hearing eyewitness accounts that differed from Winston's initial version, a source close to the situation told CNN's Rachel Nichols.
The witnesses told FSU officials that Winston was standing on a table while shouting the phrase -- something Winston initially denied, the source said. Winston also initially downplayed the incident, but he admitted the full story after university officials confronted him with the witness accounts, according to the source.
Redshirt sophomore Sean Maguire replaced Winston for the defending national champions (2-0) against Clemson (1-1).
The game was Saturday's only match between two ranked teams. Clemson is No. 22 in the AP poll and No. 24 in the coaches' poll.
Winston publicly apologized Wednesday for the comments.
"I want to be out there on the field with my team, but I did something. I've got to accept my consequences," Winston told reporters.
"I messed up. And I got to accept the fact that I did that. It eats me alive, man, that I did something like that. I can't carry myself that way," he added.
This isn't the first off-field allegation that has attracted headlines for Winston.
After a woman accused Winston of sexually assaulting her in December 2012, a Florida prosecutor announced last December that no charges would be filed in the case.
The accuser alleged Winston had raped her after she had been drinking with friends at a bar; Winston maintained that the sexual activity was consensual.
The prosecutor said authorities did not have probable cause to arrest Winston in the case.
Florida State still is conducting a Title IX investigation in the case, an attorney for the accuser said this month. The Title IX law requires schools to investigate allegations of sexual assault even if criminal charges are not filed.
Winston made headlines again in April when he was accused of shoplifting crab legs and crawfish from a Publix supermarket in Tallahassee. Police said that Winston said he forgot to pay.
As part of a civil citation for alleged shoplifting -- an alternative to criminal prosecution for first-time, nonviolent offenses in Leon County -- Winston was not arrested but was ordered to serve at least 20 hours of community service, authorities said.
Winston is once again seen as an early contender for the Heisman, college football's top award. It is given in December to the player who voters believe had the best college football season.