BALTIMORE -- Left-hander Zach Britton threw off a mound Friday and remains on schedule in his rehab from an impingement in his pitching shoulder.

"Zach Britton threw off a mound today, first time, full mound," manager Buck Showalter said. "That's good. He is doing everything on the rehab calendar, falling right on schedule."

Showalter wasn't ready to announce the next steps with the prized lefty, and actually hadn't spoken with Britton after he threw an undetermined number of pitches on Friday.

"Don't ask me exactly what he is doing next, exactly when he is going to pitch in a game, but so far, so good," Showalter said.

Britton, 24, had two rounds of injection therapy in March, and it was deemed a six-week process at the time.

Johnson back with team after hospital stay

BALTIMORE -- Orioles closer Jim Johnson was back with the club on Friday, after spending four days at an area hospital because of food poisoning. He was discharged from Saint Agnes Hospital late Friday morning.

"They said I got food poisoning," Johnson said. "I just had some bad food. They were able to narrow it down and treat it."

Manager Buck Showalter wouldn't commit to Johnson's availability after the right-hander played catch Friday afternoon. Johnson wasn't sure, himself, before he threw.

"It might be a stretch, but we'll see," he said.

Johnson described himself as lethargic after spending four days at the hospital, but he said he began feeling better Thursday night -- well enough to watch the NFL Draft and some NHL hockey.

"I've been laying on my back for four days," Johnson said. "Just getting on my feet, running around, doing some card stuff was good."

Johnson said he was both frustrated and scared during the ordeal.

"It was pretty bad," Johnson said. "You're going to wash your mics after this."

Andino returns from paternity leave

BALTIMORE -- Second baseman Robert Andino returned to the Orioles Friday after spending three days in Miami for the birth of his third child.

Andino's wife, Renee, delivered a baby girl named Amarise Hazel on Wednesday -- Andino's 28th birthday.

Pitcher Jason Berken was optioned to Triple-A Norfolk on Friday to make room for Andino on the 25-man roster.

Berken, 28, was recalled from Norfolk on Wednesday when Andino left. Berken did not appear in a game.

Berken has been stellar as a starter at Norfolk, allowing just one earned run in 15 innings (0.60 ERA).

Andino was back in the lineup Friday, batting ninth and playing second base.