If Lowrie's shoulder keeps him out for some time, I think the plan B is to play the original starter (Scutaro) and having Navarro/Sutton fill in as utility guys. Sure, they'll be active trying to figure out if they can/should get this deal done, but I think there's enough internal coverage to make them not overreach, which is what I suspect it will take to get it done. At a minimum, the offer to get Reyes will have to look more appealing than the 1/1s draft picks they'll get as compensation. Then there's the added bonus it will take to make it look they aren't just bailing for their fans. Right now, the Mets have a perfectly legit excuse, the financial mess, to not sign him in the offseason and take their supplemental picks. Losing him mid-season without a "Wow" deal probably hurts them in the PR department.
I just don't see the Sox offering up enough talent to get him, but I'd be happy to be surprised.