OAKLAND -- Left-hander Brett Anderson was diagnosed with a navicular stress fracture of his right foot, revealed by CT and bone scans, the Athletics announced Friday.
Anderson will be reevaluated in four weeks, when his walking boot is removed.
"I was running in the outfield on Monday and suddenly my foot started hurting," Anderson said. "I got it checked out and this is the result."
Unfortunate turn of events...but we're a good team with or without me and hopefully I can contribute sooner rather than later.- Brett Anderson (@BrettAnderson49) May 17, 2013
Anderson has been on the disabled list since May 1 with a sprained right ankle.
"It's very unfortunate," A's manager Bob Melvin said. "In four weeks we'll get another scan and see how it's feeling."
He had posted a 1-4 record and 6.21 ERA in six games, five starts, this season, allowing 22 runs (20 earned), 32 hits and 15 walks while striking out 29 batters in 29 1/3 innings.
"I'm disappointed in myself," Anderson said. "I need to be healthy. When I'm healthy, I feel I'm one of the best pitchers. I may need to take up a hobby, maybe play darts or something."
Anderson, who is also using crutches to stay off the foot, said he is still trying to understand his circumstance.
"I'm two days from making another start and now I'm on a walking boot with a fracture in my foot."
A's add lefty Okajima to bullpen in place of Resop
OAKLAND -- Left-hander Hideki Okajima, a non-roster invitee this spring, was called up from Triple-A Sacramento, the A's announced Friday.
The A's designated right-hander Chris Resop for assignment to make room for Okajima on the 40-man roster.
Okajima was 0-1 with a 2.16 ERA and .193 opponents batting average in 14 games with the River Cats. He walked two and struck out 18 in 16 2/3 innings.
"He's been throwing the ball well, against left-handers in particular," A's manager Bob Melvin said. "It seems like you always need a couple of lefties for a game. To add another left to the mix will be good for us."
The 37-year-old left-hander has not allowed a run over his last nine games, a span of 11 innings, and has stranded all four of his inherited runners over that stretch.
This marks Okajima's sixth season in the Major Leagues as he went 17-8 with six saves and a 3.11 ERA in 261 games with the Boston Red Sox from 2007-11.
"I want to be able to pitch like I did my first year in Boston," Okajima said through an intrepreter. "I was hoping to get back to the Majors and the A's gave me the opportunity."
Resop was 1-1 with a 6.00 ERA and .293 opponents batting average in 18 games with the A's. He did not allow an earned run over his first seven games this year, but has surrendered 12 runs over his last 11 2/3 innings for a 9.26 ERA.
"Resop fits in here," Melvin said. "He had a great spring. We'll have to see if he clears waivers and we can keep him. I have nothing bad to say about him."
Young likely to return from DL on Saturday
OAKLAND -- Outfielder Chris Young went 1-for-1 with two walks in a rehab start with Triple-A Sacramento on Thursday night. He was lifted for a pinch-runner in the fifth inning after feeling some cramps.
"We took him out to be proactive," A's manager Bob Melvin said. "If everything goes well today, we'll activate him tomorrow."
Young was scheduled to do some running in the outfield and to take batting practice.
"I'm optimistic I can come back tomorrow," Young said. "It sucks watching from the sidelines."
Young strained a left quad muscle during the A's 19-inning game on April 29. He was a late game replacement and had two hits before coming out.
"The last thing I want to do is come back and reaggravate something," Young said. "The more I move around, the more comfortable I feel."
• Infielder Eric Sogard and team mascot Stomper visited Stege Elementary School in Richmond, Calif., on Friday to launch the 2013 "Science of the Game" program, a partnership between the Oakland A's, Chevron and Bay Area schools. Sogard distributed "Science of the Game" workbooks to approximately 100 fourth- and fifth-graders, worked through science problems with students and rewarded them with autographed A's hats.
• Hiro Nakajima batted second, played shortstop, and was 1 for 4 with a strikeout at Triple-A Sacramento on Thursday night. He's batting .242 with the River Cats.
• The A's are 1-6 against the AL Central entering play Friday.
Rick Eymer is a contributor to MLB.com This story was not subject to the approval of Major League Baseball or its clubs.