The bulk of the Mariners' major league roster is occupied by prospects who have come up through the Seattle organization, but there are some holes that still need filling and that will call for attention as the trading season heats up.
There are two evident ways to fill those holes: acquisitions on the market or call-ups from the minors.
General manager Jack Zduriencik has executed a number of useful moves over the past few years—some useful, and some that have yet to pan out—exhibiting the necessity of making trades and proving that he can extract worth from them.
There's also a plethora of talent in Mariners' affiliates Double-A Jackson and Triple-A Tacoma.
Combining those two sources, Jack Z ought to be able to fill the remaining holes in the M's lineup as 2012 progresses, so that the team will be in better shape going into 2013.
Here are the four biggest holes on the Mariners roster and potential options to fill them, plus a preview of what the 2013 opening day roster could look like.