Cincinnati (13-7), which was 10-10 at this point last season, has lost only one series this season, dropping two of three at St. Louis from April 14-16.
The Reds have gone 6-2 since that series, including a 4-1 mark on their current seven-game road trip.
Though a powerful offense has been the key to its strong start, leading the majors with 125 runs scored and 33 home runs, Cincinnati is looking for a third consecutive solid starting pitching performance.
A day after Aaron Harang threw a five-hitter in an 11-0 win over Milwaukee, Elizardo Ramirez allowed two runs and six hits in seven innings on Monday as the Reds opened this series with a 4-2 victory.
Ramirez was called up from Triple-A Louisville before the game to fill in for injured left-hander Eric Milton.
“We told (Ramirez), ‘We’re going to score some runs for you,” Cincinnati catcher Javier Valentin said. “We told him, “Just concentrate, make your pitches and locate the ball.”’
The Reds look for a similar performance from another unheralded starter on Tuesday as Dave Williams (0-2, 10.50 ERA) takes the mound. Williams is off to a bad start, giving up 15 runs and 19 hits, including four homers, through just 12 innings in three outings.
He avoided a third consecutive loss on Thursday as he allowed six runs, eight hits and four walks in three innings of a 12-8 victory over Milwaukee.
Williams has no decisions and pitched only 8 2-3 innings in two career starts against the Nationals.
He will face Washington left-hander Billy Traber (1-0, 4.76), who helped manager Frank Robinson post his 1,000th victory on Thursday as he made his first major league appearance in more than two years.
Traber allowed four runs—three earned—and only two hits in 5 2-3 innings of a 10-4 win over Philadelphia. The left-hander missed the 2004 season after having Tommy John surgery on his elbow and pitched in the minors for Cleveland last year.
“I was a little bit nervous, but I get nervous for any game really. It’s kind of the deal,” Traber said after his first big-league game since Sept. 16, 2003.
Traber won his only career start against Cincinnati, giving up five hits and striking out five in a 3-0 victory over the Reds in June 2003 while playing for the Indians.
He’ll hope to prevent Brandon Phillips from getting back on a hot streak. The second baseman went 1-for-4 without a run scored or RBI on Monday after hitting .452 with three homers and 17 RBIs in seven games last week.
The Reds have won nine of their last 10 games against Washington.
The Nationals are 1-5 at home this season.