Addison Russell's woes have been revealed to be caused by shoulder discomfort. Ultimately, that's a good thing, as it provides an explanation for why he's had a tough time at second. Injuries and underperformance have taken a toll on the Cubs, with Jason Heyward, Kyle Hendricks and Ben Zobrist taking recent trips to the DL and Kyle Schwarber working on his swing in triple-A. Things won't get any easier as they open up a four-game set in Washington, DC against a Nationals team that is firing on all cylinders.