The Orioles would like Fox to clear waivers so he can be outrighted to Triple-A Norfolk.
"I don't know how likely that is, but that's our preference," said president of baseball operations Andy MacPhail.
Otherwise, MacPhail will attempt to trade Fox and get something in return.
First baseman Derrek Lee is close to going on an injury rehab assignment and returning to the Orioles' lineup. With Craig Tatum backing up catcher Matt Wieters, the at-bats weren't going to be available to Fox, who was 6-for-20 with two home runs against right-handers, but only 3-for-28 with no homers or RBIs against lefties.
"He's just so much better against right-handers than left-handers and he doesn't fit as well as he did a year ago," MacPhail said. "He still has some ability, but he's just not as good a fit this year."
Reporters from The Sun and MLB.com first tweeted the roster move a few minutes ago from Seattle.
Fox was the talk of spring training while hitting 10 home runs, but he batted .188 with two homers and four RBIs in 19 games during the regular season. He made only 12 starts, including six behind the plate, where his defense and pitch selection came under heavy scrutiny.
Relievers Chris Jakubauskas and Pedro Viola remain in the bullpen. They appeared to be vulnerable with Matusz's return today.