According to ESPN's Buster Olney, the Giants may be trying to block the Cardinals' efforts to improve themselves at the hot corner.
it's unclear how San Francisco would do so, since its record is currently ever so slightly better than that of St. Louis, so the Cardinals would have priority in a waiver claim situation. The Giants are 67-52 with a .563 winning percentage while the Cardinals are 65-51, a .560 winning percentage.
But how much of a letdown is it that the Cardinals were once expected to walk away with the National League Central crown and now they're in a waiver wire showdown over a potential competitor for the wild card?
Even if the Giants were in front of the Cardinals in the waiver department, they might have to make a pretty expensive investment to try to shut out St. Louis altogether. There are several mediocre third basemen said to be negotiating the waiver process including Toronto's Edwin Encarnacion, Houston's Geoff Blum (.265/0/16), Toronton's Edwin Encarnacion (.244/13/36), Milwaukee's Craig Counsell (.246/1/16) and Detroit's Brandon Inge (.252/7/44) head up the list.