Manager Brian Snitker said Saturday the four players, including right-hander Touki Toussaint and infielder Pete Kozma, agreed to have the team disclose their positive tests.
Snitker said Freeman had a negative intake test before having a positive test on Friday. Snitker said the first baseman has a fever and "is not feeling great."
Major League Baseball has scheduled the 60-game season to start on July 23. Freeman is the biggest star in the sport so far to have his positive virus test publicly announced by his team.
Snitker said Smith and Toussaint have no symptoms. He said Kozma, who is working with top minor leaguers at the team's Triple-A Gwinnett facilty, has a fever.