Chris Carpenter was designated for assignment on Tuesday in order to make room on the 40-man roster for Mike Napoli. If Carpenter as the piece the Red Sox could designate and not miss wasn't a surprise, then it's fair to say the rumor that the Cubs are interested in reacquiring him is a level beyond that. Let's go with "expected" or "predictable." Bruce Levine:
A source with knowledge of the situation indicated the Cubs would be interested in signing him if he is put on waivers.
Like Boston, the Cubs also have a full 40-man roster, which would most likely preclude a trade between the clubs.
If the Cubs do claim Carpenter, whom they sent to Boston along with Aaron Kurcz as compensation for the departed Theo Epstein, then they would then need to designate someone to make room. Sadly, they no longer have Sandy Rosario, so we can't restart that whole bit of off-season fun. The Red Sox might see a piece they would like that isn't on the Cubs' 40-man roster, however, and if the Cubs are willing to part ways in order to bring Carpenter back, then maybe there is a deal to work out after all.
If the Red Sox can make a trade in the next 10 days, they won't need to put Carpenter on waivers, where he could be lost. If no one claims him -- presumably Boston's hope -- then he can be re-signed to a minor-league deal, and the fact it's his final option year will no longer matter.