A pitch from A's right-hander Clayton Mortensen nailed Johjima on his left elbow.
After several minutes of treatment from the team's medical staff, Johjima went to first base and eventually advanced to third base. He caught the top of the second inning, but rookie Adam Moore batted for Johjima in the bottom of the inning.
Johjima suffered a contusion of the left elbow, but X-rays were negative.
Johjima went into the game with a .251 batting average, nine home runs and 22 RBIs.
It is the second time this season he had to leave a game against the Athletics prematurely. He suffered a broken left big toe on May 25 in a home plate collision with Oakland infielder Adam Kennedy.
Johjima ended up missing 26 games.
Jim Street is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.