Arizona @ Washington preview

Last Meeting ( Aug 19, 2014 ) Arizona 1, Washington 8

The Washington Nationals look to keep rolling as they try for their ninth consecutive victory when they host the Arizona Diamondbacks in the third contest of their four-game series Wednesday. Washington refuses to give up any ground to second-place Atlanta in the National League East as it posted its season-high eighth straight win with an 8-1 triumph on Tuesday. Stephen Strasburg scattered three hits over eight dominant innings and Ian Desmond collected three hits and four RBIs as the Nationals maintained their six-game lead over the Braves, who are in the midst of a five-game winning streak of their own.

Washington is 5-0 on its 10-game homestand and has scored at least five runs five times during its winning streak. David Peralta accounted for Arizona's lone run with his second homer in as many days as the club fell to 2-6 on its 10-game road trip. The Diamondbacks have lost four in a row, surrendering a total of 23 runs over the last three defeats.

TV: 7:05 p.m. ET, FSN Arizona, MASN (Washington)

PITCHING MATCHUP: Diamondbacks RH Trevor Cahill (3-8, 4.68 ERA) vs. Nationals RH Tanner Roark (12-7, 2.93)

Cahill is coming off his second straight victory, a triumph at Miami on Friday in which he allowed two runs over 6 2/3 innings. The 26-year-old has yielded three earned runs or fewer in each of his six starts since returning to the rotation and a total of five in his last three outings. Cahill has not pitched well in three career turns against Washington, going 1-2 with a 5.40 ERA.

Roark got back in the win column Friday, defeating Pittsburgh despite yielding three runs on five hits and two walks in 5 2/3 innings. The 27-year-old went two straight turns without a victory after a four-start winning streak that saw him allow one run over seven frames in each triumph. Roark made his only career start against Arizona in his final outing of 2013 and settled for a no-decision after giving up just one unearned run and three hits in seven innings.

WALK-OFFS

1. Nationals CF Denard Span enters Wednesday with a 22-game hitting streak at home.

2. Arizona CF Ender Inciarte's career-best hitting streak was halted at 17 games while 1B Mark Trumbo had his run of reaching base safely end at 17 straight contests.

3. Washington OF Nate McLouth is done for the season due to a torn labrum in his right shoulder. The 32-year-old, who batted .173 with one homer and seven RBIs in 79 games, will undergo surgery Thursday.

PREDICTION: Diamondbacks 3, Nationals 2