Nam Y. Huh/AP

After Monday’s game in Philadelphia, the first game he took in as a member of the Nationals, Scott Hairston was given word from Manager Davey Johnson, through bench coach Randy Knorr, that he would hit leadoff the next day. Cole Hamels, one of the left-handed pitchers that right-handed Hairston has torched in his career, was scheduled to start.

Hairston understands why he was brought to Washington and what will be expected of him in a bench role. He can play any outfield position, although he is most comfortable in the corner spots, and can mash left-handers. So in his first full day as a National, he was thrust atop the order and straight into action. It will be the 100th time he has started a game as a leadoff hitter, spot where he has a career .288 average and .898 OPS.

“I’m OK with it,” he said of hitting leadoff before Tuesday’s game. “I think when it matters the most is the first at-bat of the game. After that, it really doesn’t come into play as much. I just try to have a really good at-bat when I’m leading off. I know I haven’t in a while, but for the most part, I don’t change my approach because I’ve learned that I do better when I don’t think about it as much. Just go out and try to get on base.”

In order to start Hairston and hit him leadoff, Manager Davey Johnson rested everyday center fielder Denard Span, who has struggled against left-handers this season. Bryce Harper, who has always loved his time in center field and jumped at the opportunity, will return to center for the night. Hairston will start in left. In his career, Hamels had shut down the Nationals to the tune of a 2.64 ERA over 25 starts. Hairston, picked up at the right time for the Nationals, is 12-for-30 with five doubles and five home runs against Hamels.

“Pitch around this guy,” Johnson said, as if warning Hamels. “The other guys can hit behind him, too.”

Span is hitting .154 against left-handers this season, far below his career average of .278. Johnson believes the center fielder will snap out of it, as he pulls out of his overall hitting struggles. Sitting Span for Hairston against future tough left-handers is a possibility, too.

“It will send a message around the league that I will use Hairston in his spot,” Johnson said. “It also causes some problems for the other managers. When they go to their bullpen in a lefty situation, I might could use Hairston. That prevents them from doing that and enables Spanny to hit. So it just opens up more options and creates match-up problems for the other managers.”

Hairston doesn’t attribute his success against Hamels to anything specific other than seeing the ball against him. In fact, Hairston admits he sees the ball better out of most southpaws’ hands than right-handers.

“I pick up the ball better against lefties, pick the ball up sooner,” he said. “And I think that split-second or half a second, whatever you want to call it, that makes a difference in the at-bat sometimes. And that’s really the only explanation. Left-handers are releasing the ball, I’m a right-handed hitter, so they’re releasing it further away from me. Sometimes when it’s righty-on-righty, the guy releases the ball behind you, it’s hard to pick up.”