SAN FRANCISCO — Buster Posey once played all nine positions in a college game, but he was drafted as a catcher, retired as a catcher and will go into the Hall of Fame as a catcher. That means that for as long as he is running baseball operations for the Giants, any catcher who is acquired will merit a bit more attention. The most notable newcomer to the position arrived at Oracle Park on Monday afternoon, although Jesús Rodríguez might not get into a game this week. Acquired at the deadline in the Camilo Doval trade, Rodríguez was brought to San Francisco to be on the taxi squad and gain experience with a big league staff that he might be catching next season. The 23-year-old said he was excited for the opportunity to get a look at life in a big league clubhouse. He hopes to make a good impression, and team executives certainly will be watching him closely. Rodríguez was the main piece in the deal that sent Doval to the New York Yankees.“We wanted to take a hard look at him in spring training,” manager Bob Melvin said. “That was the key guy in the trade. Buster really wanted him. Yeah, he’s definitely in the...