Adam LaRoche didn't perform well in his last visit to the postseason, but his recent performance – especially against his former team – suggests he wants to make amends. LaRoche and the Washington Nationals seek a season-high sixth straight win on Sunday when they eye a three-game home sweep of the Pittsburgh Pirates. The 11-year veteran, who played in 375 games for Pittsburgh from 2007-09, went 3-for-21 in the 2012 National League Divisional Series as Washington lost in five games to St. Louis.

LaRoche entered the month hitting .266 with 13 home runs and 55 RBIs, but has been on a tear in August – batting .333 with five homers and 11 RBIs – and is 3-for-7 with a home run and four RBIs in this series. Saturday's 4-3 win allowed the Nationals to maintain a six-game lead in the NL East while also knocking the Pirates out of the second wild-card spot in the NL. Pittsburgh, which matched a season high with its fourth straight loss and trails Milwaukee by 4 ½ games in the NL Central, is in danger of losing the seven-game season series after winning the first three meetings.

TV: 5:05 p.m. ET, ROOT (Pittsburgh), MASN 2 (Washington)

PITCHING MATCHUP: Pirates RH Edinson Volquez (10-7, 3.67 ERA) vs. Nationals RH Doug Fister (12-3, 2.34)

The Pirates' only 10-game winner, Volquez secured his sixth victory over his last seven decisions after permitting two runs on five hits over six innings in Tuesday's 4-2 win over Detroit. Although the 31-year-old Dominican has given up 15 homers in 2014, he has surrendered only five over his last 14 outings. Volquez got the win in his only turn versus the Nationals on May 22 – allowing one run in six frames – to improve to 2-2 with a 5.47 ERA in five all-time starts against them.

Fister cruised to his sixth win in his last seven turns in Tuesday's 7-1 victory over the New York Mets, yielding seven hits in seven scoreless frames. The former seventh-round pick of the Seattle Mariners hasn't allowed an earned run in three of his last four outings and is 6-1 with a 2.01 ERA at home, where he is holding opponents to a .213 average. Fister posted his second win of the season versus the Pirates on May 25 – allowing a run over 5 1/3 innings – and is 1-1 with a 1.47 ERA in three career starts against them.

WALK-OFFS

1. Nineteen of the last 24 games in this series have been decided by two runs or fewer.

2. LaRoche, who is a career .352 hitter against the Pirates, has belted all five of his August homers in the last 10 contests after going deep once over previous 29 games.

3. Nationals RF Jayson Werth reported tenderness in his ailing right shoulder after a batting practice session on Saturday and may not return as planned on Sunday, according to the Washington Post.

PREDICTION: Nationals 3, Pirates 1