Marlins ace Josh Johnson has stopped his throwing program because of lingering discomfort in his right shoulder, raising doubts about whether he'll return next month as the team had hoped.

Johnson will have the shoulder examined Wednesday by orthopedist Dr. James Andrews before the team determines when he can resume throwing.

"It's not great,' baseball operations president Larry Beinfest said Tuesday before the Marlins opened a three-game series against the Athletics.

"He threw a (bullpen) on Friday and reported a little bit more stiffness and it just didn't feel right. We set him up to go see Andrews. Obviously, it's not what we were looking for in the progression.'

Johnson, a two-time All-Star, was 3-1 with a 1.64 ERA over his first nine starts before experiencing shoulder tightness. He resumed throwing off a mound June 17, leading the Marlins to believe he could return to the rotation July 16 against the Cubs in Chicago.

"That's obviously in jeopardy now,' Beinfest said.

Beinfest said the team isn't ready to give up yet on Johnson returning this year.

"We'll leave that up to the doctors,' he said. "We wanted to make sure we made every step and didn't cut any corners to make sure it was right. That's the progression we were on. He's just not ready to push through that right now.'

The Marlins have been a mess since Johnson went on the disabled list May 21 . They were 3-22 in June going into Tuesday.

"Any time you're missing a guy who's your No. 1 starter it's going to do damage to your rotation,' pitching coach Randy St. Claire said. "Not having that guy in your rotation is huge."

Johnson hasn't thrown a full bullpen session since Friday, which was his third. Last week, he had ultrasound taken on his right knee, a procedure the team said was not serious.