FORT LAUDERDALE, Fla. — The Orioles have shut down right-hander Jim Johnson for at least a week so they can try to determine the cause of discomfort in his right shoulder.

"We don't just want to treat the symptoms, we want to figure out why we're having the problem," Johnson said on Sunday, adding that he will be limited to conditioning work for the next week or so, but believes he can be ready for opening day April 6.

Johnson noticed the discomfort during the last couple of pitches of his last outing on Wednesday, and again when he was lifting weights after that game. He says the pain is identical to the impingement in his right shoulder that put him on the disabled list for the final five weeks of last season.

"It's just a little barking. ... We'll treat it with some medicine," he said. "Time is the biggest luxury we have right now. We're trying to figure it out so it doesn't become a problem during the season."

Johnson was one of Baltimore's most reliable bullpen arms last season, going 2-4 with a 2.23 ERA in 54 games without allowing a home run as the team's primary setup man.