Left Field is a question mark, and so is 3rd base. In left, they have two options, either go sign or trade for a big hitting left fielder, or move Brandon Belt there. He has indicated a willingness to play left field, and defensively he's as good as most out there. Of course, at first base he's excellent defensively. So perhaps the question will be answered by whether they have more luck in bringing on a corner outfielder or first baseman.
As to 3rd, I have it on good authority (as in from someone associated with the organization) that they are very fed up with Sandoval's weight problems and not inclined to put up with another year of him resembling a Kodiak Bear more than a Panda. Don't be too surprised if they trade him, probably to an American League team. If they do, they have a couple options. Bring in a new 3rd baseman, or move Buster Posey out from behind the disk and put him at 3rd. Remember, he played shortstop in college (in addition to closing games on the mound), so he's very capable of playing a good defensive 3rd base. Or, they may trade Hector Sanchez for a 3rd baseman, as Sanchez is one of the most asked for players in trade talks.
Any way you slice it, 2014 is going to be an interesting season. After this year, I guess we can all pray that Angel Pagan stays healthy. Their record, with and without him, is markedly different.