Regardless of Posey leaving, out two biggest needs are still at backup C and backuip PG, in that order. We can probably get by OK with one of our draft picks (or even TA?) as the wing defender, but if Perk or Rondo goes down, we're up the proverbial creek without a paddle.
Now that the Spurs used up most of their MLE on Roger Mason (I think, Roy?), we should be able to outbid them for Kurt Thomas. He'd be perfect: he has enough of a shot to spread the floor; he's a proven winner; he can defend the post, and he rebounds.
He'd be my #1 target (and VT Hillbilly's, who convinced me of all this). It'd probably take most or all of the MLE, but the Spurs only have about $2.3 million of their's left.
My first point is that if Rondo goes out, no matter who we have backing up the 1, we're probably up the proverbial creek without a paddle. So I would probably look at who fits best in the backup role rather than who could man the post for the long term if he goes out.
Thomas is interesting though. He bangs, he's tough, he had decent range for a big man, he could fill P.J.'s shoes nicely.