Maybe another bullpen arm or some middle infield prospects (either at 2B, SS, or 3B) or a young power bat at 1B. Depending on who you give up you could maybe get one of our young pitchers like Rohrbough or Medlen. Idk a whole lot about Detroit's farm system.
We would probably put Thames out in left and let him split AB's with Matt Diaz, but he definitely has more home run power than either of those guys so he'd be a worthwhile pickup. Anderson for Thames doesn't seem all that bad, especially since Marcus is playing like shit for you and it seems as if you're taking more of a "win now" approach. Garret would be a nice lefty bat either off the bench or maybe in the #6 or #7 slot - in my Braves chise he hit 38 2B's in close to 400 AB's, so he's a great gap hitter.
And yeah, lol...our farm system is loaded. Hanson, Heyward, Freeman, Medlen, Rohrbough, Schafer, Hicks, Kimbrel, and all them. Future looks good.