"Logan was with Cincinnati and he's been working out and is ready to go," Orioles manager Buck Showalter said. "He pitched real well over there and has a lot of experience here in the States, too. He was one of the better relief pitchers over there. So we were able to add him through a lot of diligent work by a lot of people.
"He is, we hope, just another quality guy down there that has a fresh arm and is ready to go. He's shown a background being able to defend himself against left-handed hitters, which has been a challenge for us. Evidenced by yesterday['s loss] in Minnesota. [We're] hoping he can help us in that department."
Ondrusek went 8-3 with a 2.17 ERA in 102 games with the Tokyo Yakult Swallows of Japan's Central League over the last two seasons, including a 3-1 record and 2.45 ERA in 30 games this season. In 281 career Major League games, Ondrusek is 21-11 with a 3.89 ERA and 214 strikeouts in 270 2/3 innings.
"Ondrusek is a proven Major League pitcher with good stuff, and we believe he can help our Major League club now," executive vice president of baseball operations Dan Duquette said.
Roe, 29, went 1-0 with a 3.72 ERA and 11 strikeouts in nine games for the Orioles this season. He allowed four earned runs over 9 2/3 innings.
Brittany Ghiroli has covered the Orioles for MLB.com since 2010. Read her blog, Britt's Bird Watch, follow her on Facebook and Twitter @britt_ghiroli, and listen to her podcast. This story was not subject to the approval of Major League Baseball or its clubs.