2:35pm: The Orioles have announced the move. Left-hander Donnie Hart has been optioned to Triple-A Norfolk, leaving Richard Bleier as the lone southpaw in manager Buck Showalter’s bullpen.

8:33am: The Orioles will select the contract of veteran right-hander Edwin Jackson, reports Eduardo A. Encina of the Baltimore Sun. The team has an open 40-man spot after outrighting left-hander Paul Fry last week, so the team need only make a corresponding 25-man roster move.

Jackson’s minor league deal with Baltimore contained a June 1 opt-out date that he agreed to push back to this past Monday, as Encina originally reported. By triggering that clause, Jackson gave the O’s 48 hours to add him to the Major League roster or grant him his release, and the team has opted for the former option.

Through 20 1/3 innings with the Orioles’ Triple-A affiliate in Norfolk, the 33-year-old Jackson has turned in a very solid 3.10 ERA with 7.5 K/9, 4.4 BB/9 and a 32.1 percent ground-ball rate. He’s been particularly effective lately, with three straight scoreless appearances — a total of 5 2/3 innings. Jackson has worked primarily in a multi-inning relief role with the Tides and is likely to occupy that same role initially with the Orioles, per Encina. Baltimore does have some instability in its rotation, however, so it’s at least feasible that Jackson could return to a starting gig down the line if he performs well out of the ’pen.

Notably, the Orioles will be the 12th Major League team for which Jackson will appear in his career. That puts him just one club shy of the Major League record, which is currently held by Octavio Dotel, who played for 13 teams. Jackson has previously suited up for the Dodgers, Rays, Tigers, D-backs, White Sox, Cardinals, Nationals, Cubs, Braves, Marlins and Padres. In 1724 1/3 innings at the Major League level, he has a career 4.65 ERA with 6.9 K/9, 3.6 BB/9 and a 44 percent ground-ball rate.