The Los Angeles Dodgers lost a difficult series to start this homestand, though it should get easier now against two division opponents they have dominated.
Los Angeles (78-62) dropped two of three to NL East-leading Washington after falling 8-5 in 14 innings Wednesday. The Dodgers are now two games behind the Nationals in the race for the No. 1 seed in the postseason.
Manager Don Mattingly wasn't too disappointed since his club maintained a two-game advantage in the West over San Francisco.
"I don't think this game comes back to haunt us. I think this was a good game for us," Mattingly said. "The positive side of this is that the effort and determination and perseverance from our guys is going to get us where we want to go. Our guys fought all day."
The Dodgers' remaining opponents on their homestand are Arizona (59-81) and San Diego, two clubs they have gone a combined 22-10 against this season - including a 12-4 mark versus the Diamondbacks.
Arizona will play after firing general manager Kevin Towers earlier in the day. Towers was named GM in 2010 and assembled a roster that won 94 games and the NL West in 2011.
Los Angeles chose to start Carlos Frias on Wednesday to give Haren (11-10, 4.27 ERA) two extra days of rest. Haren is 2-2 with a 3.90 ERA with at least six days' rest this year. He last pitched when he allowed two unearned runs over six innings in a 3-2, 12-inning defeat to the Padres last Friday.
The veteran right-hander is 3-1 with a 2.15 ERA in his last five outings, and 3-1 with a 4.26 ERA in four against Arizona this year.
Chris Owings is an astounding 7 for 8 off Haren this year and 9 for 11 in his career. A.J. Pollock is 4 for 6 with two doubles in their matchups.
The Dodgers are hitting .238 against left-handers for baseball's third-worst average as they seek to get untracked in their first look at Arizona's Vidal Nuno (0-4, 3.23).
The Diamondbacks have dropped nine of 10 starts by Nuno, who was acquired July 6 from the New York Yankees. He has pitched well in posting a 2.25 ERA in his last four outings.
The only decision he received in that span happened when he gave up one run in eight innings in Saturday's 2-0 defeat to Colorado, retiring his final 20 hitters.
"I don't know what more he can do," manager Kirk Gibson said. "He gave up a home run and retired 20 in a row. He didn't walk anybody. He struck out seven guys. It is a shame."
Dodgers slugger Adrian Gonzalez has a team-high 92 RBIs but is a .198 hitter against lefties - one of baseball's worst marks.
Los Angeles may be concerned about the enigmatic Yasiel Puig, who is mired in a 4-for-37 slump with one extra-base hit in his last 14 games.
The Diamondbacks head up the freeway after capturing the final two games for a four-game split in San Diego. Pollock and Owings combined for five hits in Thursday's 5-1 win.
Arizona has allowed three runs or fewer in eight straight games, the club's longest streak since doing so in nine consecutive games from Sept. 25, 2005, to April 5, 2006.