We've discussed Danny Espinosa landing on the DL and Anthony Rendon getting called up and getting a shot at earning significant playing time at second base. Now let's talk about the other roster moves the Nationals made today - their decision to designate right-hander Henry Rodriguez and left-hander Zach Duke for assignment and call up left-handed reliever Ian Krol from Double-A Harrisburg. Rodriguez was originally acquired by the Nats along with outfielder Corey Brown in the Josh Willingham trade back in the winter of 2010. Since then, it's been a constant struggle as the Nats have tried to give Rodriguez an opportunity to let his immense talent show at the major league level while also needing to pick their spots with him wisely due to his extreme inconsistency and wildness. The flame-throwing right-hander is ridiculously talented, having a fastball that has reached 102 mph this season, a knee-buckling curveball and a changeup that he throws harder than many pitchers throw their fastball. But control has always been Rodriguez's Achilles heel. He's walked 6.1 batters per nine innings for his career, and he had 16 walks, a hit batter and two wild pitches in 18 innings pitched this season. Manager Davey Johnson often needed to have another reliever warming when he inserted Rodriguez into games, and he was unable to trust Rodriguez in high-leverage spots. After Rodriguez allowed the game-winning run in the 10th inning of a loss to the Braves on Saturday, the Nats decided that a team with World Series aspirations couldn't continue to carry a reliever that was in many ways still a project.

"It's very difficult," general manager Mike Rizzo said. "He was a guy we traded for, we liked at the time of the trade, we thought that we could make him an impact-type of reliever and it just didn't work out for us. His stuff is well-documented, you've all seen it, and on occasion he can dominate a baseball game. "We were trying to be as patient as we could with it but it was time, in the situation that we're in now, it was time for us - it's a performance league, as I've said many times. When you're not performing, we've got to find the combination that will help us win as many games as possible." Rodriguez sat at his locker packing up his things this afternoon, uncertain of where he's headed next. Players that have been designated for assignment are exposed to waivers, and any team can put in a claim and take the player's contract. If the player clears waivers, the original team (in this case, the Nats) have 10 days from the day the player is designated for assignment to either trade him, release him or outright him to a minor league affiliate. "I got a long time off, no pitching, and I started coming back and started feeling good, and I think I got a little bad luck," Rodriguez said. "I worked every day to try and get better. It's hard to understand it. "I don't want to stay inconsistent, but sometimes I look at my videos, I look at the strike zone, I throw a pitch for a strike and the umpire don't call it. There's no frustration. I feel good and I'm waiting for another team to give me an opportunity again." Like Rodriguez, Duke will hit the waiver wire, and the 29 other teams will have a chance to claim the 30-year-old left-hander, who posted an 8.71 ERA in 12 appearances (one start) this season. He struggled mightily against left-handed hitters, who hit .448 off Duke this season. Duke has been a starter for much of his career, and had trouble adjusting to the role of a long reliever, where his work was inconsistent and he was unsure of when he'd pitch next. "Duke, I really like him as a starter," Johnson said. "The starting staff we've got, I haven't needed a lot of long men. His situation was very tough. Having to start an inning maybe once every 10 days or so, that's very difficult. He relies on change of speeds and location and stuff. He's a guy that has been starting his whole life." Johnson said he was confident that both Rodriguez and Duke would be picked up by some team on waivers. Rizzo chose not to speculate. "We're going to go through the process and we'll see what happens," Rizzo said. If Rodriguez clears waivers, the Nats would surely welcome him back and allow him to try and work out his control issues at Triple-A Syracuse. Duke would be more of a question. Krol, meanwhile, is a highly talented left-handed reliever who came to the Nats this offseason as the player to be named in the Michael Morse trade. The 22-year-old allowed just two earned runs in 26 innings at Double-A Harrisburg this season, striking out 29 and walking seven. He held left-handed hitters to a .122 batting average.