HOUSTON -- Joc Pederson was a rookie of the year front-runner and the starting center fielder for the National League All-Star team, but a protracted slump has cost him his starting job with the Los Angeles Dodgers.

Manager Don Mattingly said Enrique Hernandez will take over the center-field job until further notice. Hernandez was in the starting lineup against the Houston Astros for the second straight day and will face right-hander Lance McCullers on Sunday.

"It's just that time of year. [Hernandez] has been swinging the bat better. He's comparable defensively. It's just one of those things that we have to do at this point," Mattingly said. "I can't say it's going to stay that way if [Hernandez] goes in the tank or something. At this point, he has earned at-bats, and I feel like it gives us a better chance to win."

Pederson, 23, is hitting .163 with a .333 on-base percentage and .293 slugging percentage since the All-Star break. For the season, he is batting .214 with a .798 OPS and has struck out in 29.4 percent of his plate appearances.

Of his 23 home runs, 20 came before the break. Pederson finished as the runner-up to Todd Frazier in the home run derby the day before the All-Star Game in Cincinnati.

Joc Pederson is hitting .122 in August. Doug Pensinger/Getty Images

The Dodgers, who lead the San Francisco Giants in the NL West by 1½ games, went into Sunday on a four-game losing streak.

"We have no problem with Joc. It's not like he's been a prospect that comes up and just doesn't care," Mattingly said. "He's totally actually the other direction, probably cares too much, probably letting it bother him too much. I have no doubt that Joc's going to end up being a great player. But at this moment, we feel like Enrique is a better alternative."

Hernandez, 23, has hit .294 with an .840 OPS this year and has played better-than-expected defense in center field. He was acquired as a utility player in a seven-player trade with the Miami Marlins at the winter meetings and has played five positions this season.

The Dodgers acquired Chase Utley to play second base while Howie Kendrick is out with a strained hamstring in part so that they could use Hernandez in center field.

Pederson's inability to put more balls in play has been a frustration for Mattingly, his field staff and the analytically oriented front office of Andrew Friedman. Hitting coach Mark McGwire has worked with Pederson extensively on shortening his swing, but the slump has persisted.

Mattingly met with Pederson on Sunday morning to discuss the new arrangement.

"I don't necessarily know if it's now or it will take until the offseason when he can really make true changes," Mattingly said. "But you can't just say, 'Hey, we'll wait until next year.' I think you try to go to work. He's been trying to do it, so hopefully they'll fall into place for him."