The club announced that the 26-year-old Mata cleared waivers, thus removing him from the team's 40-man roster and adding Berken. Mata made his Major League debut on May 26 and pitched to a 7.79 ERA (17.1 IP, 15 ER) in 15 games with the Orioles.
A pleasant surprise for the O's, Berken posted a 1.95 ERA before the All-Star break, holding opponents to a .235 average in his first 32 career games out of the bullpen. But he posted a 7.71 ERA in nine games after the break, prompting the Orioles to check out his right shoulder, where they discovered a labrum tear.
Berken chose to forgo surgery and is optimistic that his offseason rehab regimen will get him back on track in time for Spring Training.
Brittany Ghiroli is a reporter for MLB.com. Read her blog, Britt's Bird Watch, and follow her on Twitter @britt_ghiroli. This story was not subject to the approval of Major League Baseball or its clubs.