After facing two of the most dominant arms in the National League, the Rockies' scuffling offense should earn a much-needed break when Dan Haren takes the mound for the Nationals on Saturday.
Against Jordan Zimmermann and Stephen Strasburg -- owners of two of the 10 best ERAs in the NL -- the Rockies scored only two runs through the first two games of their four-game series in Washington. But Haren (4-8, 5.72 ERA) has allowed at least four runs in six innings or fewer in each of his last three starts.
"I tried to keep my head in the game," Haren said after allowing four runs in six innings against the Phillies on Monday. "I was better than I had been. I was able to get six innings, I guess it's better than five. I'm still looking for improvement. I wish I could have given the team more."
It will be Haren's second start against Colorado after he surrendered five runs and eight hits in five innings at Coors Field on June 11.
Haren's issues have stemmed from not being able to keep the ball inside the park -- the 18 home runs he has allowed this year are the most in the league.
Still in search of a win on its road trip, Colorado is under .500 for the first time since Opening Day. The Rockies will turn to Jhoulys Chacin (5-3, 4.26) to rescue them from a season-worst five-game losing streak.
Chacin is just six days removed from his best start of the year, as he came an out away from his first shutout in more than two years Sunday. He ultimately gave up two runs before he was pulled after 8 2/3 against the Phillies, but he needed only 86 pitches to make it that far.
The Nationals are riding a three-game winning streak, their first three-game winning streak since May 8-10.
Rockies: Dickerson earns promotion at long last
For months, outfielder Corey Dickerson has posted numbers dominant enough to earn a spot on most big league rosters. But with a surplus of impact bats in the Rockies' outfield, Dickerson was stuck in the Minors before he finally got the long-awaited callup Friday.
In his first season of Triple-A ball at Colorado Springs, Dickerson has established himself as one of the most lethal bats in the Pacific Coast League. His .386 average, 13 triples and 1.042 OPS led the PCL, and Dickerson also showed significant power with nine homers and 38 RBIs.
Dickerson joined the Rockies for Spring Training before heading to Colorado Springs, hitting .333 in 27 at-bats.
Nationals: Zimmerman fighting through slump
Nationals third baseman Ryan Zimmerman, a cornerstone of Washington's franchise, is battling his way through a three-week hitting slump.
Since May 29, when he blasted three home runs against the Orioles at Camden Yards, Zimmerman is 17-for-79 with 24 strikeouts in 10 games, good for just a .215 average.
But Nationals manager Davey Johnson is confident it is only a matter of time before his third baseman, who has never finished a season with an average lower than .266, rediscovers his rhythm in the batters' box.
"He knows what he needs to do," Johnson said. "A lot of times it's the way different guys pitch to you. A lot of times he'll look for pitches and sometimes you can go in a slump looking in the wrong spots. But he's too gifted. He'll hit."
Zimmerman's numbers on the year are still solid -- he's hitting .268 with eight homers and 34 RBIs and drove in a run with a double in Friday's win.
• Haren has served up 16 homers in nine career starts at Coors Field, but has allowed only four home runs in six starts against the Rockies away from Denver's thin air.
• Michael Cuddyer's hitting streak is now at 19 games, the Rockies' longest streak since Larry Walker hit in 21 straight in 1999.
• Nationals shortstop Ian Desmond has homered in three straight games, his solo shot in the seventh Friday night handing the Nationals the winning run.
Ian McCue is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.