I would have thought that Brian Sabean had his hands full traveling to watch Urbina throw.
It should be noted that KNBR has been supporting Sabean in his defense from the "Lunatic Fringe" (Sabean and assistant GM, Ned Colletti, are regular guests on KNBR), so it would surprise me if KNBR would jump on top of a bunch of fluff that would put Sabean in peril.
However, the crux of this rumor does make some sense. If the Astros are out, they’re going to have to cut bait with Beltran. Cain is one of the top pitching prospects in the minors. The Marlins have been looking for a young catcher for a while now, and the Giants have two of them in Yorvit and A.J. And Beltran would immediately improve the Giants offense and defense.