Adam Eaton is working through left knee soreness as the Nationals' season winds down. (Matt Slocum/Associated Press)

For the second straight game, Washington Nationals Manager Dave Martinez has prospect Victor Robles playing center field and batting first in the lineup.

That is, in part, because Martinez wants to see the 21-year-old play as much as possible before the team breaks for the offseason at month’s end. But it is also because Adam Eaton, the everyday right fielder, is dealing with soreness in his left knee. It is the same knee in which Eaton suffered a torn anterior cruciate ligament and meniscus in April 2017, an injury that kept him out for most of last season and turned this year into a test of his durability.

The left knee has not been an issue in 2018 — at least not until this point — but Eaton did spend close to two months on the disabled list after undergoing left ankle surgery. Now Eaton is dealing with knee soreness, and it seems that the Nationals, more than anything, are just being extra cautious as the final week of the season nears.

“I’m just giving him a couple days off,” Martinez said before the Nationals’ matchup with the New York Mets on Friday night at Nationals Park. “He pinch-hit yesterday and he said he felt okay, but we kind of just want to keep him off and let Victor play a little bit, and make sure that he will be okay.”

“He said it’s just stiff, so I told him to take a couple days off,” Martinez continued. “At this point, I don’t want him re-injuring anything.”

Eaton last started against the Marlins in Miami on Tuesday, and he finished 2 for 3 with a run and an RBI. His scrappy style — sliding hard into bases, always busting out of the box, not shying away from outfield walls — provides reasonable concern about playing him when he is not 100 percent. But it is also what gives the Nationals an edge atop the order whenever the 29-year-old plays, as Eaton is hitting .294 and has scored 49 runs in 89 games. He is expected to be in the Nationals' outfield for at least one more season; he has one more year remaining on his contract before the organization holds team options for 2020 and 2021.

Robles has gotten an extended opportunity in his place, and he struggled while going 1 for 6 with four strikeouts in the Nationals' 5-4, 12-inning loss to the Mets on Thursday. He will have another chance to find a rhythm at the plate Friday against Mets ace Jacob deGrom, and Martinez and the Nationals will use that as another chance to take stock of their future.

"Yesterday, the situation arises where he could have won the game, and I know that’s a big moment for him,” Martinez said when asked whether Robles was trying to do too much at the plate. “He’s young, and he needs to learn what he can and what he can’t do in those moments. But so far, I really love what I see from him, just watching him in the dugout and his excitement, his energy, it’s awesome, and he loves to play.”

LINEUPS

METS (71-82)

Amed Rosario SS

Jeff McNeil 2B

Michael Conforto LF

Jay Bruce RF

Brandon Nimmo CF

Dominic Smith 1B

Todd Frazier 3B

Devin Mesoraco C

Jacob deGrom P

NATIONALS (77-76)

Victor Robles CF

Trea Turner SS

Bryce Harper RF

Anthony Rendon 3B

Juan Soto LF

Ryan Zimmerman 1B

Wilmer Difo 2B

Spencer Kieboom C

Joe Ross P

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