They also signed right-hander Ryan Mattheus to a Major League deal.
Bisenius, 28, made five relief appearances for the Nationals in 2010, allowing five runs and 4 2/3 innings, after going 4-0 with a 3.05 ERA and 10.8 strikeouts per nine innings in 34 appearances at three levels in Washington's Minor League system.
Wood, 28, went 1-1 with one save, four holds and a 4.32 ERA in 44 relief appearances spanning two seasons (2009-10) with the Marlins. Over the past three seasons, he is 8-6 with one save and a 3.55 ERA in 84 games (one start) in the Minors.
A former first-round selection (11th overall in 2003 First-Year Player Draft) and top 10 prospect for the Indians, Aubrey, 28, hit six home runs with 17 RBIs in 46 big league games with the Indians (2008) and Orioles ('09).
Bixler, 28, hit .340 with eight extra-base hits, 19 RBIs and six stolen bases in 27 games last season with Syracuse of the Triple-A International League after being acquired from the Pirates on Aug. 7. A second-round selection by the Pirates in 2004, he appeared in 68 games with Pittsburgh from 2008-09.
Frazier is coming off a 25-home run, 73-RBI All-Star campaign with Triple-A Toledo. The 28-year-old also saw his first big league action last season, playing in nine games with the Tigers. Frazier was a third-round pick by Detroit in 2004 and has hit .276 with 77 home runs and 420 RBIs in seven Minor League seasons.
Van Every, 31, had a .255 batting average with two home runs and nine RBIs in 40 big league games with the Red Sox from 2008-10.
As for Mattheus, 27, he went 1-1 with a 0.79 ERA in 10 games/four starts last season with the Nationals' Gulf Coast League team and New York-Penn League affiliates in his first action since undergoing Tommy John ligament replacement surgery in July 2009.
After shifting to the bullpen for the first time in 2008, he saved 17 games with Double-A Tulsa and represented the Colorado Rockies in both the '08 All-Star Futures Game and Texas League All-Star Game. The 27-year-old was acquired by Washington as part of a three-player trade that sent left-hander Joe Beimel to Colorado on July 31, 2009.
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He also could be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.