The Red Sox have had 5 guys play 3rd this season. The ONLY one who has not committed an error is Selsky, who managed to make the play on the only chance he got in the 3 2/3 inning he played there,
The sorry stats are:
Sandoval 16 games, 139 1/3 innings, 36 chances, 4 errors
Hernandez 9 games, 72 innings, 25 chances, 5 errors
Rutledge 3 games, 27 innings, 9 chances, 2 errors
Holt 1 game, 8 innings, 2 chances, 1 error
Selsky 1 game, 3 2/3 innings, 1 chance, 0 errors
That doesn't even account for balls that get by through the hole for hits that most 3rd basemen make. I don't understand all the advanced fielding metrics, but there's not a single one of the ones listed in Baseball Reference that's a positive number, which can't be good.