Redmond, originally a 39th-round selection by Pittsburgh in the 2004 First-Year Player Draft, made a spot start for the Reds last August, his only career big league appearance. In that outing, he allowed four runs on seven hits and issued five walks over 3 1/3 innings.
Across eight Minor League seasons, Redmond, 27, totes a 71-61 record and 3.58 ERA in 207 games (200 starts). Last season, he went 8-11 with a 3.63 ERA in 26 contests between the Triple-A affiliates of the Braves and Reds. He tallied 136 strikeouts over 148 2/3 frames.
The Orioles acquired Robinson in November from Seattle in exchange for second baseman Robert Andino. Robinson is a .215 hitter over parts of two seasons with the Mariners. He carries an average of .281 in eight Minor League campaigns. He batted .265 with nine homers and 41 RBIs in 83 games for Triple-A Tacoma last season.
In a separate transaction, catcher Luis Martinez cleared waivers and was outrighted to Triple-A Norfolk. The 27-year-old, who logged two hits in 18 at-bats (.111) for the Rangers last season, received a non-roster invitation to Spring Training. Baltimore selected Martinez off waivers from Texas last month.
Zack Meisel is a reporter for MLB.com. Follow him on Twitter @zackmeisel. This story was not subject to the approval of Major League Baseball or its clubs.