I don't think it would necessarily require a sharp decline for him to stay put. Even a modest decline might do it.
He'll be 33, and if he doesn't opt out he'll be guaranteed 2 years and 38.75 million. That's really not bad for an aging DH.
If the Red Sox sole purpose this offseason was to get under 208 million, they could have traded Mookie for a couple of middling prospects and been done with it.
With Lester, they f***ed up before the season started.
Lester seems to have given them a legit shot to sign him, even after being traded.
Theo just blew everyone away with his offer.