Although the Giants are done with all of their big spending for the offseason, they are definitely not done with all of their moves. Even though the Giants have a solid, if not spectacular, major league rotation, pitchers can are fragile players and can be easily hurt. The Giants should currently be looking to add depth to the AAA rotation.
The first option I see is to resign Jonathan Sanchez. He will obviously come very cheap considering his 1-9 record and 8.07 ERA. While many may think his career is over, I think his best shot at a revival is going back to the Giants organization. He pitched well with the Giants, and the pitching coaches will already have a pretty good understanding of how he pitches, and how he can improve.
The knock on Sanchez is obviously that he declined in every single statistical area. He walked people more, struck people out less, gave up lots of hits, and extra base hits. I do believe that he could work with the Giants coaches to at least be a good AAA ace. This is also a low risk, high reward signing
Option number two is Jair Jurrjens. He is just a year removed from a season where he went 13-6 with a 2.96 ERA. He is another pitcher that took a huge statistical hit last season all across the board. He also has trouble staying healthy, which likely contributes to his struggles. This would be another low risk high reward signing. I also imagine the opportunity to pitch at ATNT would be good for Jair, who is, and always has been, a contact pitcher.