Rodriguez, 26, went 0-1 with a 4.00 ERA (8 ER/18.0 IP) in 17 relief appearances with the Nationals this season. The righthander limited opponents to a .203 batting average against (14-for-69), including a .194 mark by right-handers and a .211 mark by lefthanders. Rodriguez was designated for assignment on June 4.
The native of Venezuela has pitched all or part of five major league seasons with the Oakland Athletics (2009-10) and the Nationals (2011-13), going 5-7 with 11 saves and a 4.23 ERA (68 ER/144.2 IP) in 143 relief appearances. He has struck out 149 batters in 144.2 innings pitched. In his first season with the Nationals in 2011, Rodriguez went 3-3 with two saves and a 3.56 ERA (26 ER/65.2 IP) in 59 relief appearances, setting career bests in wins, ERA and outings. He set a career high with nine saves with the Nationals last season.
Dickson, 22, is 2-2 with a 6.88 ERA (27 ER/35.1 IP) in 11 appearances (three starts) with Single-A Kane County this season. He was originally selected by the Cubs in the 35th round of the 2011 Draft.
Sanchez, 24, is 0-1 with a 9.82 ERA (8 ER/7.1 IP) in six relief appearances with Triple-A Iowa this season. He was claimed off waivers by the Cubs from the Cardinals on May 21.