This helpful rundown by Dave Cameron at Fangraphs on the changes to the CBA and their effect on the free agent market this winter contains an interesting theory about how something similar to the NBA's "sign and trade" phenomena could become an attractive strategy for some MLB teams to try to reallocate money to player development in light of draft/IFA spending restraints in the CBA:

Let’s just say make up an example to show how this might work. The Houston Astros have a massive amount of budget space this year, but they’re unlikely to sign a multitude of impact free agents to improve the team’s talent base from 65 wins to 75 wins, since they’re in full scale rebuilding mode. The CBA won’t allow them to simply shift that money to the draft or international free agency, so their only real choice is to spend it on Major League players. But there’s no rule that says they have to keep those Major League players.

Say — and again, I’m making all of this up for illustration purposes only — the Astros hear through the grapevine that Shaun Marcum is asking for $8 million on a one year deal in order to build back up his value and hit the market again next winter, and that the Royals are interested in bringing him in, but aren’t sure they can afford to sign him and still have money to afford Anibal Sanchez, who is their primary pitching target. The Astros could then approach both Marcum and the Royals and suggest that a sign-and-trade is in everyone’s best interests. The Astros would sign Marcum for $8.5 million — enough of an incentive to get him to go along with the plan — and then immediately trade him to Kansas City in exchange for, say, Lorenzo Cain, while picking up the tab for the entirety of the contract Marcum just signed. (Royals fans, don’t freak out. The actual names don’t matter. This is just an illustration.)

The Royals would essentially get the Major League free agent they wanted without increasing their payroll, allowing them to pursue everyone else on their target list, while the Astros would spend their Major League surplus acquiring guys with more long term value than the veterans who populate free agency. And Marcum would get $500,000 for the trouble of agreeing to waive the provision that says a player can’t be traded without his consent until June 15th after signing a free agent contract. He’d get a little more money, the Astros would put their budget surplus to better use, and the Royals could essentially trade for a free agent in order to keep their payroll flexibility.

Previously, there just wasn’t an incentive to pull off these kinds of moves, since Major League payroll could be reallocated to the budgets for the draft or international free agency, but the new limitations cut off that avenue for increased spending while rebuilding. While I don’t expect any teams to pursue this course, it is possible that a team like the Astros or Cubs could take some of their Major League payroll and use it to essentially establish sign-and-trades in MLB. Whether the commissioner’s office would go along with such transactions is an open question, but from my reading of the CBA, there’s nothing prohibiting a team from trying.

I could definitely see Epstein considering something like this. I'm sure the backlash from the fans would be somewhat severe if he tried it. I'm also not sure if the market conditions are such that a team would need to trade for a just signed free agent.

One scenario I could envision would be signing a closer candidate like Joakim Soria or Rafael Soriano (guys who teams might be scared to give big deals to) and then shipping them to a contender at a salary discount for prospects. In theory though, it could work with any FA whom a team might be happy to have over a prospect but not want to pay for.