MIAMI -- Once Josh Johnson fessed up that his throwing shoulder hurt, he felt better.

Now the Florida Marlins ace hopes a stint on the disabled list will allow him to quickly heal. Inflammation in Johnson's right shoulder sent him to the DL on Saturday.

Although Johnson is tied for the major league lead with a 1.64 ERA, the back of his shoulder has bothered him all season. He didn't tell the Marlins about the extent of the soreness and stiffness until Thursday after a bullpen session.

"It took everything I had to go and say something," he said. "Once I did, it was something lifted off my shoulders. Let's get it right and get it back to feeling like it did at the beginning of the season."

The move is retroactive to Tuesday, meaning Johnson might only miss two starts. The Marlins hope he'll be able to pitch the first day he's eligible to come off the DL, which would be June 1 at Arizona.

Johnson's not sure he'll hit that target date.

"I'm hoping," he said. "You never know with this kind of stuff. You've got to get all the inflammation out of there. From there it should be fine."

Right-hander Jay Buente was selected from Triple-A New Orleans and will start Sunday against Tampa Bay for Johnson.

"He's impossible to replace," Buente said. "I'll just go out and be the pitcher I've been up to this point."

Buente was converted to a starter this season at New Orleans, where he went 3-0 with a 1.94 ERA in 10 games, including five starts.

Because of poor run support, Johnson is only 3-1 in nine starts, but opponents are batting .185 against him, lowest in the NL. Last year Johnson went 11-6, made the All-Star team for the second consecutive time and led the NL with an ERA of 2.30.

Rays manager Joe Maddon was sorry to learn about Johnson's injury.

"People might think I'm nuts, but I really would have liked to see him pitch Sunday," Maddon said. "I like the idea of facing the best. You see how you stack up. Hopefully we'll get him next time."

The DL stint is the first for Johnson since he underwent reconstructive elbow surgery in 2008, but he was shut out down for the final three weeks of last season because of an ailing back and shoulder.

His current shoulder discomfort is less severe than last season, he said.

"In September I was sore without even throwing," he said. "Now I don't feel it until I start throwing. It was something I could throw through, but now is not the time to throw through it."

The velocity of Johnson's fastball was down at least 2 to 3 mph in his most recent start Monday against the New York Mets, but he blamed cool, rainy weather. He took a line drive off his right forearm in that game and was pulled as a precaution after five innings, but his forearm was fine the next day.

Manager Edwin Rodriguez said the Marlins' medical staff is confident Johnson's shoulder will quickly mend.

"We're trying to be very careful," Rodriguez said. "They don't think it's too serious, just mild inflammation. We'll rest him the two weeks, and they think he's going to be fine."

The Marlins also transferred infielder Donnie Murphy to the 60-day disabled list with a bruised left knee.