In general, I haven't been impressed by the defense of either Jeffers or Sanchez. There are factors that are tough to evaluate, especially with as many games as I follow on the radio or Gamecast, so I can't opine so much on those. Controlling a run game isn't the tool that it used to be, as much as I dislike that. What I care about most are calling a good game (which is tough to evaluate from a fans perspective) and controlling balls in the dirt and or keeping balls in front of them. I don't think either are particularly adept at that. 2 PB each, while a small number, is quite a bit for being not quite 1/3 of the way through the season.
And offensively, it's not really a contest. Sanchez was the better bat even before his latest hot streak.
I think there's plenty of room for improvement at the position, especially defensively. It's not my highest priority, but there can be improvement there.