Zack Greinke (5-0, 2.04) vs. Jordan Zimmermann (2-1, 3.27).
But one of the few rocks we've had this season includes Zack Greinke, who is on such a roll (18 consecutive starts of 5+ innings with two runs or fewer), that the Dodgers don't want to interrupt his five-day cycle, even at the benefit of bringing ace Clayton Kershaw back. So Kershaw moves to Tuesday, and Zackster goes today.
Zimmermann won 19 as an All-Star last year, but this year has only two wins to show for his six starts, which includes a 1.2 IP performance against the Marlins (which the Nationals ended up winning). And though Zimmermann has gotten great run support from his team in his starts (9 and 10 runs in two separate outings), both he (and Greinke, for that matter) have to be tense about all those errors behind them (Washington's 27 errors have them slipping back to 26th in the majors, well behind the Dodgers' majors-leading 32 Es). Will today's session be a error-filled comedy on both sides? Or will Zimmermann be as relaxed as other Zimmermanns appear to be?
(*) if one looks really, really deep in the search results