But he has a one year contract that ends now?
Someone else will have to correct me if I'm wrong, but I'm pretty sure that Zimmerman is not eligible for arbitration or free agency until he's got 4-5 years of playing time in the majors. Which means that until then, the club basically gives him whatever contract they want every year... meaning he gets 1-year contracts for the league minimum (or slightly more). I think they're paying him about $500,000 a year right now.
As I said, this is all off the top of my head. I'm sure I got some parts wrong, but that should be close enough to correct 
Thanks. This sounds understandable.
When you're 26 or so (in Zimmy's case) there's time enough to earn some big dollars.
