Third base has been pretty bare in Atlanta since Chipper Jones retired.
Adonis Garcia manned the position in 2016 and held his own. Garcia wasn't great by any means, hitting .273/.311/.406 with a 90 wRC+ and 0.8 WAR in 134 games. That isn't very good. Garcia turned it on down the stretch (as did the rest of his teammates) and hit .293/.333/.456 in the second half.
Defense was a big concern for Adonis after a rough 2015 debut; he did improve but still graded out poorly at -7 runs saved.
Some had written Rio Ruiz off as a prospect after struggling in 2015.