In some ways, the shortcomings of a metric like wins above replacement player (or wins above replacement in more ink-frugal corners of the Internet) is what drives much of baseball's commerce. Every team's actual replacement-level player, as opposed to the generic hypothetical, varies. Yes, the Justin Upton trade was about each team's view of talent, and probably grit, but even though the Diamondbacks don't value Upton like the market may, the situation would have been totally different had Arizona's roster included only two competent outfielders rather than five.
As much as each team's easily available replacement-level players comes into play in this penthouse of the market, we will see throughout the year that it matters in the worst contracts as well. These guys take up space on rosters and even more space on payrolls when there is no suitable replacement, but when there is, that's when you may finally see action.
Sunk costs and terrible sunk costs are a fixture of the contract landscape, either because things don't work out or because teams have to overpay for the later years in order to take advantage of the earlier years at what they think will be below-market salary. For example, the Red Sox kicked Kevin Youkilis to the curb last year when Will Middlebrooks was ready to replace him at lower cost.
Many have been in the sunk cost zone for years with their teams unwilling or unable to eat the money and run. Alfonso Soriano and Vernon Wells belong in the Sunk Cost Hall of Fame, maybe even with a waiver of the five-year waiting period. Barry Zito might be provided a pass just because there is no obvious replacement even if you aren't buying his dramatics at the end of 2012.
But the rosters in 2013 have presented some more original candidates to be traded, with the old team eating much of the contract before April 1 or at the trade deadline just because the roster spot becomes more valuable in somebody else's name. Here are five possibilities: