Here, if nothing else, is a measuring stick for two of the league's best young teams.
The Pirates are off to another fast start and rank near the top of the crowded National League Central, and they'll get to test themselves against the Nationals this weekend. Washington, by contrast, has had a rough week and finds itself struggling just above the .500 mark, and it will need a strong performance against Pittsburgh to stay afloat in the NL East.
The Pirates are coming off a series loss to the Brewers, but they took series from the Phillies and Cardinals last week. Pittsburgh is 8-4 at home; A.J. Burnett will be matched against southpaw Ross Detwiler in Friday's series opener, which will see Washington activate third baseman Ryan Zimmerman from the 15-day disabled list. Stephen Strasburg will pitch the middle game of this series, and the Pirates will counter with Jeff Locke.
Detwiler racked up a 0.90 ERA in his first two starts but has lost each of his last two outings. Pittsburgh is hitting just .193 against southpaw starters this year, and franchise player Andrew McCutchen is part of that power outage. But McCutchen, batting .174 against lefties this season, hasn't lost his confidence.
"My confidence is always through the roof, regardless of the outcome," McCutchen said. "If you focus on results, it's going to be a long season. I know what I'm capable of. Just have to keep telling yourself that. I'm not result-oriented, I just think about the process."
The Pirates will have a great opportunity to make an impact in the division race this month. Pittsburgh will play 15 of its next 19 at home, and 18 of its 28 May games will be played at PNC Park. Burnett is 1-1 with a 2.89 ERA in three home starts this season, and he's gone 7-3 with a 3.33 ERA in 15 career appearances against Washington.
Burnett has won two of his last three starts -- both against St. Louis -- and has completed at least five innings in each of his first six outings. The Pirates have won 13 of their last 19 games, and crept within a half-game of the first-place Cardinals on Wednesday before enjoying a day off on Thursday.
Washington, meanwhile, is trying hard to restore its early-season momentum. The Nationals were 9-6 as recently as April 17 but went 4-8 in their next 12 games. Washington will have a brief five-game homestand after it plays Pittsburgh, but then goes on a West Coast road trip for series against Los Angeles, San Diego and San Francisco.
Nationals: Harper in lineup after X-rays negative
Outfielder Bryce Harper left Wednesday's game against the Braves with a bruise under his left shoulder blade but was back in the lineup on Thursday after X-rays came back negative.
Leading off the sixth inning on Wednesday, Harper tried to check his swing on an 0-1 pitch from starter Paul Maholm. Though he winced following the swing, he finished the at-bat, hitting a smash to first baseman Freddie Freeman on Maholm's next offering.
Harper, who described the area as "a little tight" following ice and other treatment, finished Thursday's game 0-for-4 with a walk and a strikeout.
Pirates: Martin gets rest after hot streak
Russell Martin, who got a day off on Wednesday, has been on fire for the Pirates. The veteran catcher has four home runs in his last four games and six in his last 12, and his next homer will be the 100th of his career. He homered on Tuesday night and had a two-homer performance in Pittsburgh's 9-0 victory over St. Louis on Sunday.
Martin hit .274 in April, a performance that stands in stark contrast to what he did last season. Then playing for the Yankees, he batted .167 in April and .179 in 68 games before the All-Star break.
• The Pirates have won the final game in each of their last six series.
• The Pirates are 12-4 when scoring more than four runs and 4-8 when scoring four or fewer.
• Detwiler is seeking his first career win on the road against the NL Central; he is 0-6 with a 3.98 ERA in eight career starts.
Spencer Fordin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.