Updated

The Washington Nationals have dropped each of Dan Haren's last 10 starts, and the veteran right-hander will take the hill again Monday night when the Pittsburgh Pirates visit Nationals Park to kick off a four-game set.

Haren owns a 5.61 ERA in 17 starts this season, and he has not tasted victory since May 9. However, in two starts since returning from the disabled list with right shoulder inflammation, Haren has allowed only two earned runs over 11 innings. In his last outing, he tossed six shutout innings at Miami, as he allowed only three hits while striking out seven and walking one.

For Pittsburgh, Charlie Morton has posted a 3.19 ERA in six starts since making his season debut on June 13. The right-hander is coming off a solid outing against the New York Mets on July 12, as he allowed two runs on six hits over seven innings of work.

"A very efficient outing by Charlie," Pirates manager Clint Hurdle said after the game. "A lot of balls on the ground. It's good to see him continue to get a little bit better every time he has the ball. I liked Morton's outing, then the way were able to finish up after that."

Pittsburgh, which holds the No. 1 wild card spot, entered Monday two games back of St. Louis in the National League Central standings. The Pirates avoided suffering a three-game sweep at Cincinnati over the weekend thanks to Sunday's 3-2 victory. Jeff Locke allowed only run on one hit over six innings, while Jose Tabata delivered a pinch-hit RBI single in the seventh.

The offense has hit just 2-for-40 with runners in scoring position dating back to last Sunday. Tabata's RBI single ended an 0-for-29 skid. The Pirates are an NL-worst .225 with runners in scoring position on the season.

Still, Pittsburgh leads the majors in team ERA and opponent batting average.

Washington got off to a 0-3 start on their 11-game homestand after being swept by the Dodgers over the weekend. The Nationals scored only five runs for the three-game series as they, much like Pittsburgh of late, made a habit of stranding base runners. They were 2-for-26 with runners in scoring position against L.A. and are hitting .237 in such situations on the season.

"I'm sure everyone's sick of hearing it, but it's got to turn around at some point," shortstop Ian Desmond said. "And if it doesn't, then we're going to keep on trying until we run out of time."

The Nats were out-hit, 15-4, in Sunday's 9-2 loss. While there certainly wasn't much to celebrate, Jayson Werth's solo home run in the second inning ended the team's streak of six straight games without a home run.

"I got confidence in 'em," manager Davey Johnson said. "I don't want to keep talking about the offense. That's all we seem to talk about, that and the injuries."

These teams have split the last 16 meetings since the start of the 2011 season.