It's also a matchup that features two talented right-handers whose records don't quite match with their teams' performance this season.
The Nationals' Jordan Zimmermann has pitched better than his 8-6 record, as evidenced by his sparkling 2.45 ERA.
The Astros' Lucas Harrell has managed to assemble a 9-7 record with a 3.98 ERA in the midst of what is turning out to be another disappointing season for his team.
Zimmermann was named the NL's Pitcher of the Month in July after going 4-0 in six starts, but his August got off to a shaky start in his last outing.
The ever-steady right-hander gave up five runs, four earned, on seven hits and lasted just five innings Saturday against the Marlins.
Zimmermann snapped his season-long streak of six-inning outings in the no-decision. After taking an extra day off between starts to rest a sore shoulder, he posted his first non-quality start since May 28.
Zimmermann struggled with his control even though he said his shoulder felt fine during and after the game.
"I didn't have the best control tonight," Zimmerman said after the game. "I took a few days off from throwing this week to give the shoulder a little rest. I just didn't have the feel or command."
The extra rest between starts was a good thing, Zimmerman said.
"The rest definitely helped. I felt great," he said. "Taking a few days off and I got some meds in me and it feels great now."
Harrell's nine wins are the most on the Astros staff and he is 6-1 with a 2.02 ERA in nine home starts.
He has a 2-1 record and a 2.05 ERA in his past five starts, covering 30 2/3 innings.
The ability to command at least two pitches has been a key to his success, Harrell said Wednesday.
"The last three times out, it's been a different secondary pitch," he said. "Last time out, my changeup was my second-best pitch. The time out before that, my cutter was. The time before that, my curveball was.
"It's just one of those things where I'm mixing and matching with my sinker and figuring out what's going good that day and staying with it."
Harrell has thrown 133 1/3 innings this season after pitching a career-high 161 2/3 innings in 2010 between the White Sox and Triple-A Charlotte.
He threw 146 innings in the Minors for the White Sox in 2009, and then added another 10 in the IBAF Baseball World Cup.
Harrell said nobody has mentioned anything about having him skip a start or two in the next few weeks to keep his workload from getting too high.
"If that's something they want to do, that's something that I'll have to deal with when that time comes," he said. "The big thing right now is to go out there and go six-plus innings and give the team a chance to win."
Manager Brad Mills said the team will monitor Harrell's innings.
Nationals: Morse's streak at 17
Left fielder Michael Morse extended his hitting streak to 17 games with a third-inning single on Wednesday night.
It is the Nationals' longest hitting streak of the season and the second-longest current streak in the NL behind the Marlins' Jose Reyes, who has hit in 26 straight games.
Astros: Altuve at .300
Second baseman Jose Altuve got his batting average back to .300 by going 2-for-4 in Wednesday's game.
The Astros, who lost to the Nationals, 4-3, Wednesday, are 4-33 in their past 37 games.
Nationals manager Davey Johnson got just what he needed from starting pitcher Gio Gonzalez on Wednesday -- a chance to let his overworked bullpen regroup.
Gonzalez pitched a complete game for his 14th win of the season after the Nationals bullpen had been taxed with games of 11 and 12 innings to start the series.