Daniel Murphy will play in the field for the first time this season in the majors. (Alex Brandon/Associated Press)

TORONTO — Not 24 hours ago, Nationals Manager Dave Martinez had it all planned out. He would let Daniel Murphy stay off his legs for the duration of the weekend, let him serve as the designated hitter and see how it all went. Then, a few hours later, Matt Adams tried to bunt. His left index finger did not survive the attempt unscathed. Murphy will play first base Saturday in Adams’s place, his defensive debut.

“We talked a couple days ago, and he said he felt like he was ready to play second. He played first in the minor leagues and did well,” Martinez said. “I talked to him last night, and he was all for it.”

Adams had X-rays on that finger, but it was inconclusive. Martinez said the finger is still swollen, and given the size of the bones in the area, Nationals staff could not get a good sense of the state of the finger. Doctors will look at the finger when the team returns to Washington, but Adams can already bend it, which is a good sign.

“He said he needed just a day,” Martinez said. “We’ll see where he’s at.”

Martinez could have chosen Mark Reynolds to play instead, but against right-hander Marco Estrada, Martinez chose to load his lineup with left-handed hitters instead. He put Murphy at first base. He will use Adam Eaton as his designated hitter, thereby giving his legs a break from the turf, something he hoped to do when he thought Adams would be available to provide some left-handed punch in the lineup. Reynolds has been struggling and is 3 for his last 41 after a hot start to his Nationals tenure.

Ryan Zimmerman has stopped taking batting practice with his teammates before games and has not fielded ground balls on the field yet this weekend in Toronto. Zimmerman has been out since early May with what is officially being called an oblique strain, and he seems to be doing less on-field activity rather than more — though no one with the Nationals has indicated anything more than “he is progressing” and that they are taking their time.

But with Zimmerman and Adams out, Murphy can ease back into defensive duties without having to cover as much ground as he would at second base. Wilmer Difo can play to his right and use his shortstop skill set to cover more ground. In fact, infield coordinator Tim Bogar met Murphy in the dugout before the game to tell him to keep an eye on Difo and adjust accordingly. The two have never had to work together in a game before, and Murphy assured him he looks over at the dugout for positioning advice before nearly every pitch.

The matchup also should be favorable to Murphy at first base; he will debut behind Max Scherzer, who is not a ground ball pitcher. Murphy has played 211 games at first base in his career, his second-most at any position besides second base, where he has played 763.

WASHINGTON NATIONALS (37-29)

Adam Eaton DH

Trea Turner SS

Bryce Harper RF

Anthony Rendon 3B

Daniel Murphy 1B

Juan Soto LF

Michael A. Taylor CF

Wilmer Difo 2B

Pedro Severino C

(Max Scherzer P)

TORONTO BLUE JAYS (31-38)

Curtis Granderson RF

Justin Smoak 1B

Yangervis Solarte 3B

Teoscar Hernandez LF

Kendrys Morales DH

Kevin Pillar CF

Aledmys Diaz SS

Luke Maile C

Devon Travis 2B

(Marco Estrada P)

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