All that was said above about the advantages of being a Red Sox plus he could have won 1 game in a Sox uniform and become the winningest all time Red Sox pitcher, passing Cy Young. We know how big his ego is so that should have enticed him.
Maybe it's just that the Sox are not stupid enough to throw that kinda money at a 44 year old part time player. Not enough bad things can happen to the Yankees for me and
HE'S a
Yankee.