Washington @ San Francisco preview

Last Meeting ( Aug 16, 2015 ) Washington 0, San Francisco 5

The Washington Nationals continue their nine-game road trip with four in San Francisco beginning Thursday and seem to be catching the Giants at the right time. First-place San Francisco lost nine of 11 since the All-Star break after a 2-1 setback to Cincinnati on Wednesday to see its advantage shrink to 2 1/2 games over Los Angeles in the National League West while East-leading Washington boasts a four-game advantage over Miami following Wednesday's 4-1 victory over Cleveland.

Washington is 5-6 since the break and part of the reason for its mediocrity is superstar Bryce Harper, who is 0-for-17 over his last five games and batting .177 in July to drop his season average to .237. The Giants are struggling with a 4.97 ERA in their last 11 games, dropping their season number to 3.70, and have recorded only three quality starts since the break. However, San Francisco wasted a strong performance by Madison Bumgarner on Wednesday, prompting manager Bruce Bochy to tell reporters: "It’s disappointing. To have a starter throw like that, and couldn’t get it going offensively. That’s a tough one. ... (Bumgarner) did pitch great.” San Francisco's Johnny Cueto continues his pursuit of the NL Cy Young and opposes Tanner Roark, who is coming off his first loss in more than a month.

TV: 10:15 p.m. ET, MASN2 (Washington), CSN Bay Area (San Francisco)

PITCHING MATCHUP: Nationals RH Tanner Roark (9-6, 3.05 ERA) vs. Giants RH Johnny Cueto (13-2, 2.53)

Roark allowed five runs and four hits - including two home runs for the first time this season - in five innings to snap a five-start streak in which he pitched at least seven frames, with a 5-3 loss to San Diego on Friday. The 29-year-old Illinois native was 3-0 with a 1.72 ERA in his previous five games (four starts) while earning a hold in a relief appearance prior to the All-Star break. Roark is 3-0 with a 4.30 ERA and 12 strikeouts in 14 1/3 innings in four games (one start) against San Francisco, not including a pair of relief appearances in the 2014 NL Division Series when he permitted one run in 2 1/3 frames.

Cueto received a no-decision after allowing an unearned run and striking out nine in six innings of the Giants' 2-1 victory in 12 innings at Yankee Stadium on Saturday. The 30-year-old Dominican, who tries to join Washington's Stephen Strasburg as the only 14-game winners in the NL, is 5-1 with a 2.43 ERA in nine home starts this season. Harper is 2-for-7 with three walks and two strikeouts versus Cueto, who is 7-3 with a 3.55 ERA in 11 turns and owns a 16-inning scoreless streak versus the Nationals.

WALK-OFFS

1. Washington LF Jayson Werth extended his career-best on-base streak to 30 games - the longest current run in the majors - with a walk Wednesday.

2. Giants INF Ramiro Pena was scratched Wednesday after leaving Tuesday's game with a groin injury.

3. San Francisco is 0-36 when trailing after eight innings this season.

PREDICTION: Giants 3, Nationals 2