Home plate umpire Adrian Johnson left the game between the Oakland Athletics and the San Francisco Giants in the fourth inning with an undisclosed injury.Home plate umpire Angel Hernandez, center, talks with Oakland Athletics manager Bob Melvin, left, and third base coach Mike Gallego, right, in the fourth inning of their interleague baseball game against the San Francisco Giants Thursday, July 10, 2014, in San Francisco. Hernandez replaced umpire Adrian Johnson who left the game earlier in the inning.