The NL East foes begin a three-game series in Washington on Monday with the Nationals vying for their 13th home win in 14 tries against the Marlins.
The Nationals (25-25) have won five of six against the Marlins (26-25) this season - including a three-game home sweep April 8-10 - and 12 of 13 in Washington since the start of 2013, a stretch in which they've held Miami to 23 runs and a .203 average.
Tanner Roark will try to keep those stingy numbers going. Roark (3-2, 3.42 ERA) has been strong in his last three starts with a 1.93 ERA and .174 opponent batting average, though he took the loss in Wednesday's 2-1 defeat against Cincinnati. The right-hander gave up two runs - one earned - and six hits in six innings.
It'll be his second start of the season against Miami. In two career starts and two relief appearances against the Marlins, he's 1-0 with a 1.76 ERA.
The Nationals ended a four-game skid with Sunday's 5-2 victory in Pittsburgh to avoid a four-game sweep. Denard Span went 2 for 5 and is batting .382 in his last seven games to raise his average from .236 to .264, while Jayson Werth also collected a pair of hits after going 3 for 28 in his past seven.
The Nationals are working through plenty of injuries to key players, but Ian Desmond thinks they can do better with their available tools.
"It's nice to see we've stayed afloat," Desmond told the team's official website. "But I'm at the point where I know we have to play better - I have to play better personally, and we have to play better as a team."
Miami completed a six-game homestand with an even record and now heads back out on the road with a 6-17 away mark weighing it down.
Sunday's 7-1 loss to Milwaukee featured a pair of errors, and the Marlins have made seven in their last five games. The 40 they've committed are among the most in baseball, though the Nationals still lead them with 44.
Their only offense came on a solo shot by center fielder Marcell Ozuna, who improved to 7 for 19 with three homers and eight RBIs in five games.
Nathan Eovaldi will try to keep the Marlins from falling back to .500 by winning consecutive starts for the first time in his career. Eovaldi (3-2, 3.41) collected a victory in Wednesday's 14-5 home win over Philadelphia, surrendering three runs - one earned - and a season-high 10 hits in six innings.
He had allowed 11 earned runs in his previous three starts, and though his latest outing looked better in the run column, his manager saw some continuing trends.
"His last couple starts have been a little like that where he's been a little erratic in the zone," Marlins manager Mike Redmond told the team's official website. "He's left some off-speed pitches up that were hit. He did that again today. He's having a tough time right now, it seems like, finishing off hitters."
The right-hander is 1-2 with a 6.00 ERA in three career starts versus the Nationals.
Nationals first baseman Adam LaRoche, who is 4 for 8 against Eovaldi, returned to the Washington lineup Sunday and went 1 for 4. He had been out since May 10 with a strained right quadriceps.
Washington second baseman Danny Espinosa was out of the lineup Sunday after going 4 for 36 with 16 strikeouts in his previous 10 games.