Ryan Zimmerman playing left field. (Photo by John McDonnell/The Washington Post)

The Nationals will face Cardinals left-hander Jaime Garcia in Sunday’s series finale, and Manager Matt Williams said he may get Scott Hairston’s bat in the lineup in left field, give first Adam LaRoche a day off and move Ryan Zimmerman from left to first base for the first time in his major league career.

A byproduct of the return of nearly all of the Nationals’ injured starters and Zimmerman’s move to the outfield has been a dearth of playing time for bench players. But Hairston is one of seven Nationals hitters with an OPS+ above average — he has a 171 OPS+ in just 23 at-bats, including only three this month.

The Nationals have faced few left-handed starters recently and Hairston’s chances have been sparse. With Zimmerman playing left field, the Nationals have two right-handed outfielders that hit left-handed pitching well, and Denard Span has hit well over the past month and a half.

Hairston is 4 for 6 with a home run in his career against Garcia and LaRoche, who is 1 for 8 against the left-hander, has played the past 17 straight games since he returned from the disabled list on May 25.

“It’s hard because guys are back and they’re playing every day,” Williams said. “That’s kind of the situation that we’re in. [Hairston is] working every day. He’ll be ready when his name is called at any given point.”

If Williams chooses to play Zimmerman at first on Sunday, he said he is  confident the veteran can handle the position. Zimmerman entered this season expecting to spell LaRoche against left-handed pitchers at first base. He played there once during spring training. Instead, a broken thumb, a balky and chronic shoulder, and a void in left field have instead pushed Zimmerman to left field. Zimmerman, however, has still been taking pre-game grounders at first base and not third.

“He’s been doing some work,” Williams said. “He’s fine. The infield is second nature for him. It’s not anything big.”

Hairston has hit left-handed pitching well since he arrived in Washington in a mid-season trade last season. So far this year, he is 9 for 23 with a home run. Against left-handers, he 7 for 17. Hairston has been working hard in the batting cages daily to stay as fresh as possible, but seeing a batting practice pitchers isn’t the same as a 94 mph fastball from an opponent.

“I’ve been in this role quite a bit in my career,” he said. “It’s nothing new to me. Not to say that it gets easier when it happens more often, I just know how to handle it better. I recognize the situation. Obviously my role is pinch-hitting against left-handed pitchers and sometimes the situation the pitcher’s spot comes up and there’s a right-hander on the mound. Not that I can’t hit righties but my role right now is just hitting lefties. I understand that. The way things have been lining up are not in my favor.”

When Bryce Harper returns, Wiliams has said that Zimmerman will return to third base. That could mean more opportunities, too, for Hairston, who could spell either Span or Harper against tough left-handed pitchers. But Zimmerman, however, could do the same by shifting to the outfield for that match-up and Danny Espinosa could come off the bench to play second. In other words, the Nationals will have a myriad of possible defensive alignments and match-up possibilities then. Sunday could be the first such example.