The team announced the suspension on its Twitter feed, with no further explanation. Manager Fredi Gonzalez also declined to elaborate when asked about the punishment before the Braves' 10-7 victory at the Chicago Cubs.
"I'm not going to say anything other than that it's an internal matter," he said. "That's the way I like to handle stuff, and the Atlanta Braves like to handle stuff. And that's it. You can ask me 400 different ways and my way is that we're going to handle it internally."
The 34-year-old Uggla has played sparingly since rookie Tommy La Stella was promoted from Triple-A Gwinnett on May 28. The three-time All-Star is batting .162 with two homers and 10 RBIs in 48 games.
The Braves acquired Uggla in a November 2010 trade with the Marlins, and then signed the three-time All-Star to a $62 million, five-year contract before his first game with Atlanta. He is slated to make $13 million next year in his final season under the deal.
Uggla had a 33-game hitting streak and connected for 36 homers in his first season with the Braves, but most of his numbers have been trending down over the past couple of years. He hit just .179 with 22 homers and 171 strikeouts in 2013, when Atlanta won the NL East and lost to the Dodgers in the division series.
Gonzalez said he expects Uggla to be with the team when it begins the second half at home against the Phillies on Friday. He also isn't worried about the effect of the suspension on his team.
"I don't think so. I got a pretty good pulse of our clubhouse," he said. "If anybody wants to talk to me, my door is always open. And they know that."
Atlanta also promoted infielder Phil Gosselin from Triple-A Gwinnett before its series finale against the Cubs. Gosselin hit .345 with five homers and 30 RBIs in 88 games with Gwinnett.
"He's had a terrific first half of the Triple-A season," Gonzalez said.
Uggla Suspended By Braves
ESPN.com senior writer Jim Caple discusses the Braves' decision to suspend Dan Uggla for one game.