(Brian Garfinkel/GETTY IMAGES)

When Johnson offered his thoughts on Harper’s struggles, in particular against left-handers, he touched on an interesting trend he has found among young hitters, one that Danny Espinosa has been a part of as well but has been improving.

“[Harper is] hitting around .250 and he feels like he probably should hit .400,” Johnson said. “Instead of trying to be a good hitter and hit line drives everywhere, that you did more so when you first came up here, he’s now trying to juice the ball. That’s normal with his ability.”

When he first broke into the majors, Harper showed incredible ability to adjust to new challenges. Now, pitchers, especially left-handers, are exposing his weakness with offspeed pitches away. At one point in early June, Harper was crushing left-handed pitching: hitting .366 (15 for 41) with two home runs, two triples, three doubles and four walks.

In 108 at-bats since then, he is hitting .167 against left-handers. Overall, Harper is hitting .221 against left-handers and .267 against right-handers.

“They’ve really sent him a steady diet of offspeed pitches and whatever, not really attacking and going after him,” Johnson said. “And he gets impatient and then he’s his own worst enemy. Early on, they’re going to make adjustments to somebody that’s hitting them. And they made adjustments on not challenging him and more offspeed stuff. He’s impatient chasing stuff out of the zone. But that’s just part of maturing as a hitter. You gotta make adjustments on how they’re attacking you. It’s like an open book. And sometimes you’re too stubborn to read the book. It’s out there on him. But eventually they get it. And he’s been a pretty quick study.”

Johnson is of the belief — one that he learned longtime Atlanta Brave Chipper Jones shares with young players on his team — that young players shouldn’t worry about their power, and focus on hitting solidly for contact.

“A lot of young players come into the league and they think if they occasionally hit a home run that that’s better than hitting a couple line drive singles,” he said. “It’s good advice [Jones] gives to youngsters on his ball club and I’ve read comments that he’s made to that effect. That’s really the approach you have to take, be a good hitter. Guys like Rafael Palmeiro came up being good line drive hitters and then eventually the power comes. It seems to be the trend with the majority of young hitters wanting to hit the ball out of the ball park first and then become a good hitter later.”

Chris Marrero, who has been recovering from a hamstring tear last year and is at Class Syracuse Chiefs, is an example of a young hitter who focused more on hitting solid singles than smacking home runs, Johnson said. Marrero, a 2006 first-round pick, hit 17 home runs in the minor leagues in 2009, 18 in 2010 and 14 in 2011. He played 31 games for the Nationals last season and in 109 at-bats didn’t hit any, hitting .248 overall.

“And I thought Marrero came up with the idea of being a good hitter, hitting line drives and sacrifice his power to be a good hitter,” Johnson said. “And I thought he was on the right track.

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