Both teams now say they were not comfortable with particular deal. For one thing, #Athletics only would trade Cespedes for monster return.— Ken Rosenthal (@Ken_Rosenthal) December 4, 2013
It certainly backs up much of what has been suspected - that the trade of Heath Bell was not the last item, and the D-backs are looking for a power outfield arm. I
nterestingly, they appear to be thinking for the long term as well: Cespedes has only two years of service time, so would be under team contract through the end of the 2017 season. With 49 home-runs in 264 games - and that playing at home in Oakland - Cespedes would certainly deliver the kind of power missing from our outfield in 2013. But, similarly, I can also see why the Athletics would want a significant haul for a player like that.
The advantage of dealing for a pre-arbitration candidate
like Cespedes would be that it would not add much more to the salary bill for the Diamondbacks next season, allowing the balance of amount currently available (round about $11 million or so, if my math is right) to be devoted to starting pitching. Of course, the reverse would also be true: if we get a pre-arb starter, then we can spend the money on an outfielder's salary. This deal may have fallen through, but it perhaps gives an indication of the directions in which the Diamondbacks are looking to move, and may point the way toward future possible negotiations, and the packages on offer from Arizona.
Edit. It appears, contrary to what Baseball-Reference.com believes, Cespedes would only be under team control for two more years, due to the contract signed with the Cuban player. This four-year deal signed pre-2012 "precludes Oakland from offering him arbitration, meaning the outfielder will automatically become a free agent at the conclusion of the 2015 season." It also means any team trading for him, will not get a discounted rate, with Cespedes due $10.5 million for both remaining years. [Hat-tip j15emerson] On that basis, Skaggs and Pollock, each with much more team control and lower cost, doesn't sound too far off a reasonable offer to me.