Lowrie the solution at third? I doubt it. He's a decent hitter, especially for a SS, but he doesn't have the bat for corner infield. He could fill in there if needed, but then we have to put up with Green's bat at short, that's a downgrade of two positions at once. Not exactly the sort of idea you want to trot out when trying to design the best possible Red Sox lineup.
I'd rather try to fill actual holes than simply try to swap an underperforming player for another underpeforming player, if you take my meaning. Wilson is hideously inconsistent and just isn't very good with a bat in his hands. He's capable of a good year all right but the bad years outnumber the good ones about 2-1 with Wilson. And when it comes to a no bat all D SS, we already have one of those and one is about as good as another.
The hole I see that most needs filling is a lefthanded, power hitting corner infielder to give Lowell a stable, competent replacement when he needs to rest (or to play 1B and let Youk provide that replacement). Kotsay is many things, but a power hitting corner infielder is not one of them. I would gladly shelve him for someone from a list of guys like Teahen, Overbay and laRoche.