OAKLAND -- Injured Marlins ace Josh Johnson received a dose of good news Wednesday when he underwent tests and had his right shoulder examined by Dr. James Andrews in Birmingham, Ala.

"Dr. Andrews did not find any structural damage in the shoulder," Marlins president of baseball operations Larry Beinfest said in a statement released by the Marlins before they faced the Oakland A's.

Johnson, according to Beinfest, received a cortisone injection and will not throw for the next seven to 10 days. He said there is no timetable for Johnson's return to the rotation.

"As we expected, there's no issue," said Matt Sosnick, Johnson's agent.

Johnson is on the 60-day disabled list with inflammation of his right shoulder. He had been pitching bullpen sessions, but during a session on Friday he experienced tightness, and the Marlins scheduled an examination with Andrews, an orthopedic surgeon.

Before his setback, Johnson had had hoped to return in mid-July, shortly after the All-Star break, but that target will undoubtedly be pushed back.

Johnson, a two-time All-Star, is 3-1 with a 1.64 ERA in nine starts.