Afterward, Dodgers manager Don Mattingly said he didn't think the infraction was "that big a deal," but some of Puig's teammates indicated the late arrivals -- this was Puig's second benching for such an incident -- need to stop.
Puig said he didn't oversleep, but rather simply didn't know the team was taking batting practice so early. Players receive text messages telling them what time they need to be at the ballpark, but at least one player, Justin Turner, did not receive the text.
Puig said he apologized to Mattingly and his teammates after batting practice.
"I asked him for forgiveness as well as my teammates. It was my mistake," Puig said. "I'll be here early tomorrow."
Puig wasn't used as a pinch hitter because Mattingly said the situation didn't call for it. He also said he thought not allowing Puig to play was more fitting punishment than fining him a couple hundred dollars.
"He felt bad he wasn't here, and I believe that," Mattingly said. "He's a good kid. Does he have to grow up and get better? Yeah, but there's a lot of guys like that."
The Dodgers hit on the field before Friday's 4:10 p.m. ET start, a rarity for a day game. Puig emerged from the Dodgers' clubhouse at 1:26 p.m., about halfway through the session. Traffic around the stadium -- exacerbated by Friday morning commuters -- was heavy.
According to a Dodgers spokesman, Puig was unaware the team was hitting on the field. Often before day games, the Dodgers take batting practice in their indoor batting cages.
"I told him, 'Get your [butt] here on time,'" Dodgers first baseman Adrian Gonzalez said. "If he doesn't, that's up to the manager to decide what the repercussions are."
Before the switch, Kemp was slated to be on the bench, and Mattingly acknowledged the outfielder was upset about it. Kemp was activated from the disabled list before the game and proceeded to go 1-for-4 with an RBI double, as well as an error during a six-run Giants first inning.
Magic Johnson, one of the club's owners, supported the decision to bench Puig, while also saying he was happy Kemp was upset at not being in the original lineup.
"We have to remember, he's still young. So these things are going to happen," Johnson told ESPN.com's Ramona Shelburne, referring to Puig. "We don't want him late for games or anything like that. But I'm glad Don is doing what he's doing. He'll realize this is a golden opportunity for him and he has to just make the right decisions. I talked to him even this summer, and we're hoping that he'll get better making the right decisions with his life. He has to remember those decisions can also affect what you do on the baseball field."
Mattingly said the team will mix and match its outfielders (veteran Carl Crawford is also in the mix). In spring training, Kemp said he wouldn't accept the role of fourth outfielder.
"At this point, I'm going to match up as best I can," Mattingly said. "You think about it a lot. With all our guys, I worry about them emotionally and what it does to them."
Neither Kemp nor Mattingly spoke with reporters after the lineup change. Asked to elaborate on Kemp's mood after being told he wasn't starting, Mattingly said, "I think he was just upset."
Said Johnson: "I'm happy that he's upset. Now, when you get the opportunity, let's go out there and play. We want guys, when they're sitting on the bench, to be upset. We want guys who want to play. We want competitors. There's nothing wrong with that. Don knows that. If this is all we've got to go through, we're OK."
Puig was benched for an August game in Miami last season for violating a team rule and showing up late to the clubhouse. He later hit the decisive home run as a pinch hitter.
Kemp had left ankle surgery and left shoulder surgery in October, and missed the team's first five games this year. He batted .113 in 53 at-bats in minor league spring training games.
Information from The Associated Press was used in this report.