Stammen, 30, is coming off a season in which he had a 3.84 ERA in 49 relief appearances for Washington. He could be used as a long reliever or in the late innings.
Espinosa, 27, has struggled mightily at the plate the last two years, but he is an excellent defender at second base. The team is thinking about making Espinosa, a switch-hitter, a right-handed batter exclusively. In 2014, he hit .301 from the right side of the plate, .183 from the left.
Lobaton, 30, was a valuable backup catcher last season. He had a great rapport with Stephen Strasburg and Doug Fister in particular. Nationals pitchers had a 2.86 ERA when Lobaton was behind the plate.
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.