The Red Sox might or might not be seeking to sign Cody Ross after a Jacoby Ellsbury trade, but, should Ross sign with the Texas Rangers, then two problems pop up. One, Ellsbury doesn't get to go to a place where he could be utilized, closing up the market for him further, and one of Boston's potential replacements for Ellsbury would be lost in the process. That's why it's a little troubling to hear, via Ken Rosenthal, that the Rangers have met with Ross for some negotiation dinner.
The Rangers need help behind the plate, have lost relievers Koji Uehara and Mike Adams to free agency, and with Josh Hamilton gone, could benefit from another outfielder, especially one who can play center. That makes them an excellent trade partner with the Red Sox, who have depth behind the plate in Jarrod Saltalamacchia, David Ross, and Ryan Lavarnway, extra relievers on hand in Alfredo Aceves, Clayton Mortensen, and others, and Ellsbury's expiring contract and 2013 season to dangle. If the Rangers sign Ross, the reliever and catcher portion of things can still happen, but you're talking about a lesser return at this point -- Ellsbury is the center piece that would bring back the most, whether he has just the one year remaining on his contract or not.
Then again, if all the Rangers get is Ross, then Boston can peddle their wares elsewhere, and all without strengthening a team that the Red Sox will likely need to leapfrog if they plan on being in the 2013 playoff race. That, or just hold on to Ellsbury, which limits them long-term a little, but gives their 2013 chances that much more of a boost if he can return to form and stay on the field.