Right-hander Blake Treinen will make his first start since May 22 against the Pirates. Off-days and rainouts have pushed back his starts.
In his last start, Treinen was solid, but he came up short as the Pirates defeated the Nationals, 3-1.
Treinen, replacing Gio Gonzalez in the rotation, got off to a great start, retiring the first eight hitters he faced, but he faltered briefly with two outs in the third inning. He walked right-hander Edinson Volquez, allowed a single to Josh Harrison and walked Neil Walker to load the bases. Then Andrew McCutchen came to the plate and was hit by a pitch, scoring Volquez to make it a 1-0 game.
"It looked like [Treinen] lost his focus a little bit. That happens to the young guys sometimes," Nationals catcher Wilson Ramos said. "He is really good. When that guy gets a little more experience, he will be a great pitcher."
Treinen lasted 5 2/3 innings and allowed two runs on four hits. He threw 102 pitches, which was too many, in his opinion. Treinen also was not pleased that he walked five batters.
"I need to execute pitches a little better next time," Treinen said. "My stuff plays [in the big leagues]. I just have to execute pitches. Next time I'm out, I'll do a better job of it."
Padres starter Andrew Cashner will return from the disabled list on Saturday to start against the Nationals after missing nearly a month with elbow soreness. The Padres' Opening Day starter has often been a hard-luck loser this season, as he holds a strong 2.35 ERA in nine starts yet has just a 2-5 record to show for it.
Cashner has slightly changed his slider grip and release, which is suspected to have caused the initial pain.
"I'm just kind of moving my fingers on the ball where I can't wrap it, [so I] stay behind the ball," said Cashner, who reported no discomfort after throwing a simulated game Monday.
He aims to throw six innings in his first start back. "Hopefully we don't miss a beat when I come back."
San Diego could use Cashner's steady hand at the top of the rotation. The team has cycled through eight starters since Cashner last started, in a 2-1 win against the Reds on May 13. An arm injury also struck lefty Robbie Erlin after Cashner went down, forcing the Padres to give starts to usual long relievers Tim Stauffer and Donn Roach as well as Minor League starters Billy Buckner and Jesse Hahn.
In a road start against Washington on April 26, Cashner gave up four runs (two earned) and eight hits with one walk and five strikeouts. He took the loss in a 4-0 defeat.
"I'm excited any time I'm able to take the mound, but it's just more about focus than anything," Cashner said. "There's a good team coming in. I didn't pitch my best against them last time, so I'm looking to rebound."
Werth has day off
Nationals outfielder Jayson Werth was given a scheduled day off Friday. According to manager Matt Williams, Werth needed the time off because he woke up Friday morning experiencing a little stiffness. Werth has been an iron horse for the Nationals this year, playing in all 58 games prior to Friday's action.
"We thought today would be a good day for him," Williams said "We are not going to get another off-day until we get home. Long road trip."
In his Werth's place, Nate McLouth received the start in right and went 1-for-4 with two RBIs.
Time for Grandal to break out of slump
When the Padres traded catcher Nick Hundley to the Orioles two weeks ago for reliever Troy Patton, they did so hoping that Yasmani Grandal could break out of his season-long slump and team with Rene Rivera to give the Padres two legitimate options behind the plate.
But since the swap on May 24, Grandal has just one hit in 14 at-bats with two walks and seven strikeouts. His average has dropped below the Mendoza line, from .206 to .190.
"He's a guy that's never experienced this before, I don't think at any level," Padres manager Bud Black said. "Now that Yasi's healthy and we made the trade with the Orioles, Yasi just hasn't quite got where we think he's gonna be, as far as offense.
"He's doing everything he can to find his stroke. No doubt that he's probably pressed in a few at-bats, even a few games to try and get there. Where he is now, he won't end up there, I guarantee that. He'll get his starts, and if he gets his hits he'll be back in there the next day."
• Jason Lane has been scoreless for 4 1/3 innings since being recalled from the Padres.
• Anthony Rendon has a career-high nine home runs this season.
• Tanner Roark is the second Nats pitcher this year to strike out 11 or more batters and walk none. Stephen Strasburg was the first to do so.
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He also could be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.