Peralta, 33, has pitched parts of five seasons in the big leagues, earning two saves and 31 holds with a 4.61 ERA in 221 relief appearances. Peralta has posted a strikeout-to-walk ratio of 2.8-to-1 and has stranded 70 percent (123 of 176) of inherited runners during his career with the Angels (2005), Royals (2006-08) and Rockies (2009).
Kensing, 27, made 26 appearances with the Nationals in '09 after he was acquired from the Marlins on April 28. Kensing has an 8-9 record with two saves, 21 holds and a 5.81 ERA over six big league seasons.
Speier, 30, posted a 7-3 record with seven holds and a 3.99 ERA in 90 relief appearances during his four years with the Rockies (2005, '07-09). Speier recorded a career-best 3.65 ERA in 22 appearances in 2005 and has yielded just four home runs in 99 1/3 big league innings.
A 17-year pro, Burke, 38, returns for his second stint with the Nationals. A career .277 hitter in parts of seven big league campaigns, Burke first joined the organization via a trade with Seattle on Sept. 17.
Orr, 30, returns for his third season with Washington. He has tallied a .260 batting average with three homers, 35 RBIs and 13 stolen bases in 347 games during his five-year career with the Braves (2005-07) and Nationals (2008-09).
After spending the past five seasons in the White Sox (2005-09) and Mariners (2009) systems, Owens returns to the Nationals/Expos organization that originally selected him in the second round of the 2003 First-Year Player Draft. Owens, 28, has played parts of four seasons in the Majors, batting .262 with one home run, 18 RBIs and 36 stolen bases in 129 contests.
Bill Ladson is a reporter for MLB.com This story was not subject to the approval of Major League Baseball or its clubs.