The conventional wisdom is that the A's are trying to build the strongest possible team for the estimated opening of Cisco Field in 2011. With that in mind, I made the chart below. It shows all the players on the 40-man roster, plus a number of top prospects, in order to figure out which players the A's have control over until that magical 2011 date.
Basically, anyone above the red line is now trade bait. Unfortunately, six of the eleven players who can become free agents before Cisco Field opens are currently coming off injuries, and probably wouldn't fetch much in a trade until perhaps July, after they've proven themselves healthy. But Ellis, Embree, Blanton, Street and even maybe DiNardo should be popping up in trade rumors soon.