The Pirates have lost four games in a row, including a stinging late-inning defeat on Saturday. The last time they won was when Edinson Volquez pitched, a common theme in the last two months.
The 31-year-old has turned into one of the most reliable arms in their rotation, and the Pirates have lost just once with Volquez starting since June 18, going 8-1 in that span. He'll try to halt the team's losing skid in a late-afternoon tilt on Sunday in the nation's capital.
In his last nine outings, Volquez is 6-1 with a 2.30 ERA, .244 opponents' batting average and 40 strikeouts in 58 2/3 innings. Volquez allowed two runs on five hits over six innings of work in his last start and picked up his 10th win on Tuesday against Detroit.
"About time," said Volquez, who last reached double-digit wins in 2012 with San Diego. "It feels really good, and it's also a great win for the team."
The Nationals' Sunday starter, Doug Fister, is also in his first year with his team, and has pitched like the player Washington traded for in the offseason.
The right-hander has even taken it up a notch since the All-Star break, compiling a 1.06 ERA and 1.058 WHIP in his last five starts. Fister has been a standout all season, going at least seven innings in 11 of his 17 starts.
In his last four starts, Fister has gotten through seven innings each time, including Tuesday, when he didn't allow a run in seven frames against the Mets.
"Doug throws what he wants when he wants, and where he wants," Mets manager Terry Collins said afterward. "So when you go up there, and you're looking at our lineup [batters] 4-9, they're all pretty young, and he can carve you up. And he does."
Pirates: Walker scheduled to be in Sunday's lineup
Pirates manager Clint Hurdle assured reporters that Neil Walker was scheduled to be out of Saturday's starting lineup, as he continues to recover from nagging back tightness.
If the second baseman -- who entered Saturday's game in the seventh inning -- is not featured on Sunday's lineup card, however, that would be cause for concern.
Walker started in the series opener against the Nationals on Friday for just the second time in two weeks, going 1-for-4 with a double. The reoccurring back troubles had the Bucs mulling a DL move for Walker, but the ailment has improved in the last few days.
"We've mapped out a plan for us to maximize his availability," Hurdle said. "Our goal is to keep him on the field the rest of the season."
Nationals: Werth tests ailing shoulder
Jayson Werth went through a full workout on Saturday -- including running, throwing and batting practice in the cage -- as part of his continued effort to return from a sprained AC joint in his right shoulder.
But after Saturday night's walk-off victory over the Pirates, manager Matt Williams said Werth felt some discomfort as a result of the extensive baseball activity.
"It was a little tender," Williams said. "He'll get through tonight and see how he feels when he wakes up."
Werth, who is hitting .279/.370/.430 in 112 games this season, should not have to miss future time down the road because of the shoulder sprain, Williams said.
"Unless he bangs it again, unless he does something to irritate it again, I don't anticipate it would be something that would cost him games," Williams said. "But you never know. If he dives, or if he goes into a wall or something, it could jar that joint a little bit. But I think it's calmed down pretty well."
• The Nationals and Pirates have split the first six games they've played this season, making Sunday's contest a 2014 rubber match. The Bucs won last year's season series, 4-3.
• The home run Adam LaRoche hit off Tony Watson on Saturday was the first homer a left-handed batter has hit against the left-handed reliever since Baltimore's Chris Davis took Watson deep on June 13, 2012.
Stephen Pianovich is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.