There are talented MLB players who—for various reasons—fit poorly with their current organizations.
At least 10 are already on the trading block, and that is where they'll stay in 2012 until deals are consummated.
Several earn too much money on rebuilding or struggling teams. Others continue to under-perform on contenders that have better internal options. Front offices are actively shopping individuals in both scenarios.
There's no guarantee that any of these trade baits will move during the season, but behind closed doors—or more likely, closed phone lines—their futures are being negotiated.
*Salary details from baseball-reference.com