The NL East leaders, however, have yet to face them with the core of their lineup intact. That will change this weekend.
The Nationals look to exact some revenge against the only team to take a series from them since the All-Star break as they face the Phillies in Friday night's opener.
Washington (77-47) arrives in Philadelphia with a 6 1/2-game lead after taking two of three from second-place Atlanta. It had a chance for a sweep but lost Wednesday's finale 5-1.
"We gained some ground and that's what we wanted to do in this series,'' said losing pitcher Ross Detwiler. "It's tough to sweep no matter who it is.''
Despite the loss, the Nationals are 14-4 since Aug. 4, and have won six straight series since dropping two of three at home to the Phillies from July 31-Aug. 2 - the only series they've lost in the 12 they've played since the break.
Washington is 5-4 against the Phillies (58-67), though it has yet to play them at full strength.
Jayson Werth and Ryan Zimmerman have each played in four games in the season series, while Adam LaRoche, Washington's leader with 23 homers and 78 RBIs, has appeared in five and All-Star Ian Desmond has played in six.
LaRoche and Desmond have made the most of their limited time, though, with LaRoche homering twice and driving in five and Desmond hitting three homers to go with five RBIs.
Desmond, who went 5 for 12 with two homers in the Braves series, could be poised for a big game in the opener. He is 8 for 19 (.421) with a home run and two doubles lifetime against scheduled Kyle Kendrick (6-9, 4.20 ERA).
Zimmerman is a .400-hitter with a homer and seven doubles in 25 at-bats against Kendrick, who is trying to win three straight starts for the first time since his 2007 rookie season.
After being tagged for six runs in 3 1-3 innings in a 12-6 loss to Atlanta on Aug. 8, Kendrick has struck out 13 over 15 scoreless innings in winning his last two starts. In Milwaukee on Sunday, the right-hander gave up three hits and matched a career high with seven strikeouts in eight innings of an 8-0 victory.
"He looks more confident," Charlie Manuel told the Phillies' official website. "He is definitely more aggressive."
Kendrick has a 2.25 ERA in his two starts against Washington this year, but is 0-1.
The Phillies are coming off Thursday's 4-3, 11-inning win over Cincinnati to split a four-game series with the NL Central leaders. Chase Utley scored the winning run on John Mayberry Jr.'s single to lift Philadelphia to its fourth win in six games.
Jimmy Rollins is slowly coming out of his slump, going 4 for 16 with three doubles and three RBIs in his last four games after hitting .118 in his previous nine. He is 2 for 3 with a pair of solo homers lifetime against scheduled starter Edwin Jackson (7-8, 3.69).
Jackson permitted two runs, two hits and one walk while striking out a season-high 11 in seven innings against the New York Mets on Saturday, but was saddled with a 2-0 loss. It was Jackson's first defeat since yielding three runs, eight hits and four walks in 5 2-3 innings of a 3-2 setback to Philadelphia on Aug. 1.
The 10-year veteran right-hander has a 5.60 ERA in losing his three career starts to the Phillies.