The San Diego Padres moved to plug a hole behind the plate, as they acquired catcher David Ross from the Pittsburgh Pirates on Thursday in exchange for minor league infielder J.J. Furmaniak. Padres starting catcher Ramon Hernandez is expected to be out at least three weeks due to a cartilage tear in his left wrist. He's scheduled for surgery Friday. The Padres, who are clinging to a two-game lead over Arizona in the NL West, have used Robert Fick and Phil Nevin behind the plate. Ross, who has been playing at Indianapolis, was hitting just .211 at the Triple-A level. He batted .222 in 40 games for the Pirates this season and compiled a .170 average with the Dodgers last year. Furmaniak was hitting .266 with 14 homers and 47 RBI for Triple-A Portland.