Opposite dugout: Series with Nats looms large over Phillies' playoff chances

Manager: Gabe Kapler (1st season)

Record: 68-56

Last 10 games: 4-6

Who to watch: 3B Maikel Franco (.281 with 20 HR, 61 RBIs), CF Odúbel Herrera (10 HR, 62 RBIs), LF Rhys Hoskins (25 HR, 77 RBIs), 1B Carlos Santana (18 HR, 69 RBIs), RHP Zach Eflin (9-4, 3.70 ERA), RHP Aaron Nola (14-3, 3.24 ERA), RHP Seranthony Domínguez (14 saves)

Season series vs. Nationals: 6-4

Pitching probables:

Aug. 21: RHP Vince Velasquez (8-9) vs. RHP Tanner Roark (8-12), 7:05 p.m., MASN2
Aug. 22: RHP Zach Eflin (9-4) vs. RHP Stepen Strasburg (6-7), 7:05 p.m., MASN
Aug. 23: RHP Aaron Nola (14-3) vs. RHP Max Scherzer (16-5), 1:05 p.m., MASN

Inside the Phillies:

Given that they rest in second place, just one game behind the National League East-leading Braves, this three-game series against the Nationals looms large for the Phillies' postseason chances. Win two of three or sweep and the Phillies put more pressure on the Braves and some distance between themselves and the third-place Nationals. Lose two of three or be swept and they give the Nationals a chance to creep back into the NL East race. No one, save for first-year manager Gape Kapler, expected the Phillies to be in this position approaching the end of August. That they've lost three of five games entering this critical series is irrelevant; the Phillies will be looking to add to their roster - perhaps a bullpen piece or another starter - via a waiver trade before the Aug. 31 deadline.

They've already acquired infielder Asdrúbel Cabrera from the Mets and slugging first baseman Justin Bour from the Marlins, though neither deal has paid immediate dividends. Cabrera has hit just .208 in his first 20 games with the Phillies, with two homers and eight RBIs, while Bour, relegated to a bench role, is just 3-for-15 without an extra-base hit. That the Phillies are contending with an offense that ranks 29th in the majors in average (.236) and hits (986) is remarkable. Third baseman Maikel Franco has done a lot of the heavy lifting of late, batting .314/.339/.552 with seven homers and 14 RBIs in the second half. First baseman Carlos Santana shook off a slow start and a poor transition to the NL by posting a .350 on-base percentage and four homers in the second half. Left fielder Rhys Hoskins has weilded the most productive power bat, with team highs of 25 homers and 77 RBIs. But center fielder Odúbel Herrera has struggled since the All-Star break, slashing just .237/.297/.366.

Right-hander Vince Velasquez starts Tuesday's series opener and has gone 3-1 with a 2.67 ERA in his last eight games, including seven starts, since June 30. He's 2-2 with a 5.28 ERA in six career starts against the Nats, including a 2-0 mark with a 3.38 ERA in three games on South Capitol Street. Wednesday starter Zach Eflin has alternated wins and losses in his last four decisions after reeling off wins in six straight outings between June 5 and July 3. The righty has gotten five or more runs of support in eight of his 17 starts, and won his only career start at Nationals Park on June 22. Thursday's getaway day matinee provides a marquee matchup between Cy Young contenders Aaron Nola (14-3, 3.24 ERA) of the Phillies and Max Scherzer (16-5, 2.11 ERA) of the Nats. Nola has gone 8-1 with a 2.21 ERA in his past 14 starts since May 31. The right-hander is 2-0 with a 1.98 ERA in two starts versus Washington this season, and 3-4 with a 3.99 ERA in 12 career starts against the Nats.

Rookie right-hander Seranthony Domínguez has saved 14 games since ascending to ninth-inning duties for the Phillies, but of his three blown saves have come in his past five outings in back-to-back appearances in early August.