Henry Rodriguez Brian Garfinkel/Getty Images

The Nationals traded right-handed reliever Henry Rodriguez to the Chicago Cubs in exchange for right-hander Ian Dickson. After three years of hoping Rodriguez would develop into a dominant and consistent power arm in their bullpen, the Nationals have finally and completely parted ways with him.

The Nationals designated Rodriguez for assignment on June 4 and had 10 days to complete a trade, release him or place him on waivers. The Cubs took on the 26-year-old inconsistent fireballer and the Nationals acquired Dickson, a 22-year-old and 6-foot-5 pitcher in the lower rungs of the Cubs’ minor league system.

Dickson, a 35th round pick in the 2011 draft out of Lafayette College, posted a 6.68 ERA in 35 1/3 innings for the Cubs’ Class A affiliate Kane County, most as a reliever. He punched up a 8.2 strikeout rate but walked 3.8 batters per nine innings. Last season, he posted a 5.60 ERA in 62 2/3 innings over 15 starts for low-Class A Boise. Rodriguez’s trade value by hurt by his bouts of wildness.

He was a prized piece in the 2010 trade in which the Nationals send Josh Willingham to the Oakland Athletics for him and outfielder Corey Brown. In three seasons in Washington, he posted a 4.22 ERA over 111 games. He flashed otherworldly stuff but often followed up with pitches to the backstops and walks. He had a 4.00 ERA in 18 innings this season.

In a separate roster move following Tuesday’s game, the Nationals optioned right-handed starter Nate Karns to Class AA Harrisburg to make room for right-hander Ross Ohlendorf, who will be officially called up on Wednesday from Class AAA Syracuse to make the start. In three starts for injured Ross Detwiler after a surprising call-up, Karns allowed 10 over 12 innings, struck out 11 and walked six batters.