WASHINGTON -- At the beginning of the season, the Orioles' bullpen was a major strength, entering May with one of the top relief ERAs in the Major Leagues. However, with starters recently struggling to go deep into games, the relief corps is beginning to run on fumes. 

The Orioles have recalled left-handed pitcher Brandon Waddell ahead of the series finale in Washington, optioning right-hander Travis Lakins Sr. to Triple-A Norfolk. 

“Well, he hasn't pitched in a couple of days,” manager Brandon Hyde said of the roster move. “That's helpful right there.”

Waddell has just six appearances at the Major League level, the last on May 4 with the Twins --  he allowed three runs (two earned) on three hits in two-thirds of an inning.

While Hyde praised the rookie pitcher on his slider and fastball velocity, he stressed that this move was about adding an arm that would be available immediately. 

The O’s 4.26 bullpen ERA ranks among the bottom dozen in the Majors. Since May 14 -- which includes the two series against the Yankees and Rays and the first two games of the Nationals series -- the bullpen has blown two saves and has allowed 35 runs.

Baltimore is facing a stretch of 10 games in 10 days, traveling to Minnesota and to the South Side of Chicago. Hyde has stressed the need for starters to pitch deeper into games, which will be tested with Matt Harvey on the mound in Sunday’s game. In his last start, he pitched the second-shortest outing of his career, tossing just 1 2/3 innings.

Waddell was claimed off of waivers on May 8 after the Twins designated him for assignment. He made one relief appearance at Triple-A Norfolk, allowing one hit over a scoreless inning.