Chipper hasn't played since the 8th of July, after which he went on the Disabled List with a knee injury that required (relatively) minor surgery. Thanks to the All-Star break, Jones has missed only 12 games. Before going on the DL, Chipper was having a season roughly in line with his 2009 and '10 campaigns: not great, but good.
In his absence, Martin Prado's been playing third base. With Chipper back in the lineup, Prado figures to slide back to left field, which will cost Eric Hinske most of the playing time he's been getting lately.
More than anything, this just improves the Braves' depth, with Hinske or Prado available off the bench. The Braves have sometimes struggled to score runs this season, and every little bit helps. Chipper's return means somebody else is losing his spot on the 25-man roster, but no word yet on that unfortunate's identity.