It took one series for the Washington Nationals to go from contender to practically out of the NL East race, and the blame falls greatly on the bullpen.

The Nationals attempt to begin climbing back into contention Friday night in the opener of a three-game set with the Miami Marlins.

Washington (71-68) blew a chance to close the gap on division-leading New York this week in the nation's capital, getting swept in a crucial three-game series after falling 5-3 in Wednesday's finale.

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"We're obviously not where we want to be," starter Stephen Strasburg said. "We've just got to keep fighting. That's all we can do."

The bullpen getting back on track would help. The relievers took two of the three losses in the Mets series as they were tagged for 12 runs in eight innings, allowing 11 hits and walking eight.

Closer Jonathan Papelbon and setup man Drew Storen each appeared twice and gave up a run both times.

"Our bullpen is one of our strengths generally, and it hasn't been (recently)," manager Matt Williams said. "It's tough. I feel for those guys getting out there and giving up runs because they're not intending to, that's for sure."

Williams will certainly call upon his relievers again with Gio Gonzalez (10-7, 3.96 ERA) taking the ball. The left-hander's 147 2-3 innings are the fewest by any member of Washington's rotation with at least 20 starts, and he's failed to reach the seventh inning in five straight.

Gonzalez, though, has completed six innings in his last two. He halted a four-start winless streak Saturday, allowing two hits and no runs while striking out a season-high 10 in Saturday's 8-2 victory over Atlanta.

"He's got that in him every time he goes out there," slugger Bryce Harper said.

Gonzalez surrendered six runs and 10 hits in five-plus innings of a 6-2 loss at Miami on April 26 in his only game against the Marlins this year. He had a 1.13 ERA while winning his five prior matchups.

Harper had a pair of solo homers among his three hits Wednesday, and half of his 10 hits over the past six games have left the park. He leads the NL with a .336 batting average and ranks third with 36 home runs.

"The kid's showtime," shortstop Ian Desmond told MLB's official website. "He rises to the occasion. It's fun to kind of watch his maturity over the last few years. He's turned into quite the beast."

The Marlins (59-81) are on the cusp of clinching a franchise-record sixth straight losing season. However, they beat Milwaukee 5-2 on Wednesday to win for the seventh time in nine games after dropping eight of the previous 10, including two of three at Washington from Aug. 28-30.

Jarred Cosart (1-4, 5.04) is getting his second start since July 4. He allowed one run in 4 2-3 innings but was lifted after 88 pitches in Sunday's 4-3 win over the Mets, two days after being recalled from the minors.

The right-hander's pitch count is expected to be closer to 100, according to MLB's website.

He's 0-2 with a 3.63 ERA in three starts against Washington - all last season.