Milwaukee comes to Washington for three games beginning Friday after beating the Cincinnati Reds for the second straight day on Thursday.
The Brewers (75-60) got a Lorenzo Cain homer in the 11th inning for a 2-1 win that left them a half-game behind the St. Louis Cardinals for the top wild-card spot in the National League. Milwaukee is five games behind first-place Chicago in the National League Central.
Thursday's win followed Milwaukee's 13-12 victory in a 10-inning slugfest on Wednesday night.
"I think the offense looked tired," Brewers manager Craig Counsell told mlb.com after Thursday's win, "but you grind through it and you play good defense. We made pitches and Lo Cain got the big hit."
Washington (67-67) begins a 10-game homestand against NL Central entries Milwaukee, St. Louis and Chicago while trying to remain in the playoff hunt coming off a 3-3 road trip. The Nationals are 7 1/2 games behind the first-place Braves in the NL East and nearly as far back in the wild-card race with four teams ahead of them for the No. 2 spot.
Brewers right-hander Jhoulys Chacin (13-5, 3.61 ERA) opposes right-hander Tanner Roark (8-13, 3.95) in Friday's opener.
Roark has been a different pitcher since the All-Star break, stepping up when the Nationals needed someone to back up ace Max Scherzer. Roark is 5-1 with a 1.61 ERA in his last seven starts. During that stretch, he has struck out 37 batters and walked five.
"You really just feel unhittable," a grinning Roark recently told the Washington Post. "You feel like each pitch that you're about to throw is untouchable, and that's what you want as a pitcher."
He started that streak in Milwaukee when he blanked the Brewers for eight innings in a July 25 win. Roark struck out 11 and walked only one.
Last time out he was an unlucky loser against the Mets, allowing one run and four hits in six innings of a 3-0 Mets win.
Roark entered the All-Star break 3-12 -- winless since June 6 -- with a 4.87 ERA.
"It's been awesome," Nationals manager Dave Martinez told the Post regarding Roark's sharp turnaround. "Every time he goes out there we have a chance to win ballgames."
Roark is 4-1 with a 2.23 ERA in seven appearances (six starts) in his career versus the Brewers.
Milwaukee's Christian Yelich is 9-for-36 (.250) against Roark. Jonathan Schoop is 2-for-4 and both hits are homers.
Chacin has also enjoyed a strong August. After allowing eight earned runs to the Dodgers on Aug. 2, he has surrendered just six earned runs while going 3-1 over his last four starts.
"We talked in spring training that once Yelich and Cain came aboard, we kind of forgot about Chacín, and how important he can be," Counsell told the Milwaukee Journal Sentinel. "He's ended up being really important."
The Brewers are 19-9 in games Chacin has started. He's coming off a loss to the Pittsburgh Pirates in which he gave up three earned runs in six innings.
Chacin beat the Nationals on July 23. He pitched 5 2/3 innings, allowing a run and two hits while striking out nine without a walk. In his career, he's 4-2 with a 3.06 ERA in nine starts against Washington.