The Giants have scored the fewest runs in all of baseball this season and could upgrade their lineup in a number of ways. According to major league sources, San Francisco remains focused on acquiring a catcher. With Buster Posey out for the season, the Giants are using a tandem of Eli Whiteside and Chris Stewart. Neither is hitting particularly well: Whiteside .221, Stewart .156. Sources say the Giants have shown interest in Texas catcher Yorvit Torrealba, who began his career in San Francisco and has been the Rangers' primary backstop this year.