Turns out Ryan Sweeney's punch is extremely poorly timed, as he's likely out for the rest of the regular season. Ryan Kalish is widely expected to join the team in his place, though it hasn't yet been announced officially.
Tough break for the Sox, who were spoiled by their outfield depth. Losing Sweeney means losing the ability to trade Sweeney or Cody Ross, and probably Daniel Nava. When you factor in the likelihood of Carl Crawford or Jacoby Ellsbury missing more time, a trade of an outfielder now sounds unwise. It doesn't sound like the Sox are missing out on much. The Dodgers have pounced on Shane Victorino and the Giants on Hunter Pence, but the pitching market appears to be thin.
As of now, it still looks like the best bet for a trade is Kelly Shoppach for some minor prospects.