Winston, the Seminoles' quarterback, is also the closer for the baseball team. He was issued a civil citation after stealing crab legs from a Tallahassee Publix.
Winston missed a three-game series against Minnesota over the weekend while serving his suspension and performing the required community service.
"Winston is reinstated," Florida State baseball coach Mike Martin told the Tallahassee Democrat on Sunday night. "He finished his community service and as soon as he did he came over here, and we reinstated him."
Winston has not commented publicly about the incident since issuing a statement last Wednesday.
"As reported in the news, last night I received an adult civil citation for petty theft from a local supermarket," the statement read. "I went to the supermarket with the intent to purchase dinner but made a terrible mistake for which I'm taking full responsibility. In a moment of youthful ignorance, I walked out of the store without paying for one of my items. I realize that I am in the public spotlight and my conduct needs to be above reproach. I make no excuses for my actions and will learn and grow from this unfortunate situation."
Florida State's baseball team, ranked in the top 10 nationally, improved to 36-11 after sweeping Minnesota.
Winston led Florida State to the BCS national championship last season as a freshman, starring in the undefeated Seminoles' 34-31 victory over Auburn in the title game. He tossed the winning touchdown in the closing seconds.
On the season, Winston passed for 4,057 yards and 40 touchdowns with 10 interceptions.
Winston has had previous run-ins with the law, but no arrests.
In December, the state attorney in Florida decided not charge Winston after he was accused of sexually assaulting a woman at an off-campus apartment on Dec. 7, 2012.
The U.S. Department of Education's Office of Civil Rights has since opened an investigation into FSU's handling of the allegations against Winston and potential Title IX violations by the university.