Dodgers’ youthful start continues in 8-0 rout of Diamondbacks

Seven position players have won the National League rookie-of-the-year award in the in last decade, including Buster Posey, Hanley Ramirez, Ryan Braun, Ryan Howard and Bryce Harper.

Through the first 22 games of their rookie seasons, none of them had as many home runs as Joc Pederson has now. Only Geovany Soto had as many runs batted in.

Pederson blasted his fifth home run of the season Friday night in the Dodgers’ 8-0 victory over the Arizona Diamondbacks, a second-inning grand slam off Rubby De La Rosa that landed in the top half of the right-field pavilion.

Pederson is batting .300 with 14 RBIs. He continues to start in center field and was recently made the team’s leadoff hitter.

“I still need to put together quality at-bats,” Pederson said of his hot start. “It’s a long season. It’s not how you start, it’s how you finish.”

About the only reminder of his rookie status is when he is teased or pranked by his veteran teammates, like he was on this night.

When Pederson stepped into the batter’s box for the first time, a song by One Direction blared over Dodger Stadium’s public-address system. Later introductions were accompanied by music from other boy bands.

“We got some jokesters on the team,” Pederson said. “I was laughing walking up to the plate, to be honest.”

But if Pederson’s performance was the most memorable, Carlos Frias’ might have been the most important.

A day after Brandon McCarthy underwent a 90-minute operation to reconstruct his elbow, Frias delivered 5 1/3 scoreless innings in which he limited the Diamondbacks to four hits and a walk.

Frias became the eighth starting pitcher to be used by the Dodgers this season, which ties them for the most with the Tampa Bay Rays. With McCarthy sidelined until the middle of next season and Hyun-Jin Ryu still working his way back from a shoulder injury, the Dodgers have only three of their top five starting pitchers. Ryu could be sidelined for another month, if not more.

Scott Baker, another pitcher who was recently promoted from triple-A Oklahoma City, is scheduled start against the Diamondbacks on Saturday.

Manager Don Mattingly said he wanted to stabilize the rotation rather than continue to shuttle pitchers back and forth from Oklahoma City.

“But if your bullpen’s getting blown up for two, three days in a row, then you have to make some decisions and do some things differently,” Mattingly said.

No such moves were required in the wake a start in which Frias’ fastball hit 98 mph.

“When we saw him last year, he seemed like he was best when he was 93-94,” Mattingly said. “Now, we’re seeing 96-97. I don’t know if it’s earlier in the year or he’s just getting stronger as he’s getting older.”

In Mattingly’s view, whether Frias, 25, can sustain this form will depend on his ability to use his off-speed pitches.

“We just like to see him pitch more than be all power,” Mattingly said.

If Frias can’t do that, his future could be in the bullpen. Pointing to Frias’ mix of velocity and durability, Mattingly said, “Obviously, he has the arm that can go either way.”

If anything, what the 25-year-old right-hander did Friday night marked a major improvement from his last opportunity with the Dodgers.

Frias made unwanted history in a 16-2 defeat to the Colorado Rockies last year on Sept. 17, when he became the first pitcher in baseball’s modern era to give up 10 hits without recording three outs.

dylan.hernandez@latimes.com

Twitter: @dylanohernandez