The Chargers gave the Steelers all they could handle for three-plus quarter Sunday.

But the Bolts ended up with a 20-10 road loss that dropped them to 2-1 on the young season.

Here are five takeaways from Week 3:

1. Herbert leaves in 3rd quarter

The slugfest we all expected took play Sunday in Pittsburgh.

But the Chargers ran out of gas — and key players — in the second half as they suffered their first loss of the 2024 season.

"Not every game is going to be a fairytale ending," Chargers Head Coach Jim Harbaugh said.

He later added: "I thought they were fighting the whole time. A lot of good football played and then the fourth quarter wasn't our best."

Justin Herbert started at quarterback after being listed as questionable with an ankle injury. He was stellar in the first half but appeared to re-aggravate the injury midway through the third quarter.

"I did everything I could to go back in there. Just didn't feel like I could move around or really push off with it," Herbert said.

Harbaugh said his plan was to take Herbert out of the game at the first sign of a limp or any flare up of the injury. Taylor Heinicke played in relief of Herbert.

"I knew Justin wasn't going to take himself out. I told him that [Saturday]," Harbaugh said. "The plan was Taylor was going to go in.

"We were doing a good job there in the first half. Justin had a heck of a half," Harbaugh added. "He's a beast, but that wasn't ever going to be his decision to play today or stay in."

Herbert said he felt better after Saturday's walk-through and felt comfortable enough to play against a rugged Pittsburgh defense.

"My responsibility as the quarterback is to give everything I can to this team, my teammates," Herbert said. "I felt like I did that. I pushed myself but couldn't go any more.

"I had a tough time walking on it, moving on it, pushing off of it. I knew Taylor gave us a better shot to win," Herbert added as he later noted he's hopeful to play next week.

Harbaugh said Herbert unquestionably displayed the toughness he has become known for.

"There's no question about that," Harbaugh said. "Every time I think there's not another rung on the ladder that he can go in my esteem, he climbs another one.

"But I knew this a couple months ago," Harbaugh added. "Justin's the kind of guy you've got to pull back because you're never going to have to talk him into anything. He does have to be pulled back."

The loss of Herbert came on a day when the Chargers marched into Pittsburgh and went toe-to-toe with the Steelers.

The Bolts held a 10-7 halftime lead but were stymied in the second half as Herbert and others left the game due to injury.

The Chargers will now head home after a 10-day road trip to get ready for a Week 4 home date with the Chiefs.

"We'll be back, we'll be ready to roll," safety Alohi Gilman said. "We'll get back to work and get ready for KC coming up next.

"We all believe in each other, believe in the coaches," Gilman added. "We're on the right page, just got to keep our head down and not make any excuses."

Harbaugh added: "I've already learned it about our team. We work and they're not afraid of any challenge or any new challenge. It's razor sharp, credit card difference, the margin. I thought it was right there, it was back and forth, right where we thought it would be and we didn't get it done at the end there. We'll come fighting back."

2. Bolts defense hurt by penalties

The Bolts defense was fantastic in the first half Sunday.

Pittsburgh managed just 112 total yards on 27 plays and scored just seven points.

The theme of the second half, however, was multiple penalties that helped Pittsburgh gain momentum.

"That was the name of the game," Khalil Mack said. "We did a lot of shooting ourselves in the foot out there."

The trouble began on Pittsburgh's first drive of the second half when an 11-yard pass on second-and-14 turned into more due to a personal foul facemask call on Derwin James, Jr.

The penalty helped the Steelers get into field goal range and eventually tie the game at 10.

James was flagged for unnecessary roughness later in the quarter.

Pittsburgh converted on third-and-4 but the penalty on James added 15 more yards to a 15-yard completion.

"We just got to play clean," James said. "I got to look at some of mine, I didn't get to look at them. But just play clean football, I had one of them, a big one."

He later added: "I'm not here to referee. I'm playing fast, I'm not thinking about no flag."

Three plays after James' penalty, Mack was called for roughing the passer on a play where the Steelers would have faced fourth down.

"I got a roughing the passer call, I don't ever get those," Mack said. "It was a unique game today but they were the better team."

Pittsburgh later added a field goal to take a 13-10 lead they wouldn't give up.

The backbreaker for the Bolts defense came just over the midway point of the fourth quarter when Pittsburgh scored on a 55-yard touchdown pass to put the game out of reach.

"Yeah, they got the momentum at that point and kept it, held on to it," Harbaugh said of the third quarter. "That's the way it went.

"Any kind of drive, any kind of points, three and outs, those give momentum," Harbaugh added. "We weren't able to get it back and hold onto it."

The Chargers allowed 346 total yards to Pittsburgh and allowed the Steelers to convert half of their 14 third-down attempts.

Harbaugh said Joey Bosa re-aggravated his hip on the first play of the game Sunday. With Bud Dupree already dealing with an illness, Bosa's loss limited the Bolts edge rotation they had used in recent weeks.

"A player like Joey, everybody wants him on the field, especially with the rotation like we're used to doing first couple of games," Dupree said.

Mack added: "First play of the game, that was a huge blow."

3. Heinicke steps in

When Herbert went out, the Bolts went with Heinicke instead of Easton Stick as the backup quarterback.

The Chargers traded for Heinicke in late August in a deal with Atlanta.

"Taylor and Easton got the same amount of reps and towards the end of the week, I gave more to Taylor because I thought he was going to give us the best chance of winning," Harbaugh said.

Heinicke completed both of his passes for 24 yards but was sacked three times in his Chargers debut.

He said he felt ready to go even though his first appearance came in a hostile road environment.

"It's a difficult spot, but I feel like kind of my whole career has been like that, backup ready to go throughout my career," Heinicke said. "Had a lot of chances to play. It wasn't something new but playing this defense at their place on a home opener, it was tough."

Harbaugh said he came away "pleased" at Heinicke's performance but noted he wasn't going into delve into the backup quarterback depth chart after the game.

Heinicke said he's going to continue to dive into the playbook in case he has to start in Week 4.

"It's kind of been my main goal, just to learn the playbook as fast as possible just in case something like that did happen," Heinicke said. "I'm trying to stay out of Justin and Easton's way, kind of let them game plan and have myself learn the playbook, have dove into it the last three weeks, feel a lot more comfortable with it.

"Again, we'll see what happens next week," Heinicke added.

4. Shuffling the O-line

Perhaps the most glaring stat from the Chargers Week 3 loss was this:

In the first half Sunday, the Bolts didn't allow a single sack.

But in the second half, Pittsburgh got home five times against both Herbert and Heinicke.

The through line between those two stats was that the Bolts played most of the second half without star left tackle Rashawn Slater, who left the game with a pectoral injury.

"Just being the leader of out O-line, being a guy who's as consistent as he is, as talented as he is, it's going to be tough to kind of make that," Jamaree Salyer said of losing Slater. "But that's what we practice for, it's what other guys who aren't starters practice for, to be ready for that moment because it's a long season.

"Something is bound to happen, that's just the nature of the game," Salyer said.

When Slater went out, Trey Pipkins III moved from right guard to left tackle as Salyer stepped in at right guard.

"We feel like Trey's our next best guy, he's our third tackle," Harbaugh said.

Herbert was sacked twice in the second half. Heinicke was sacked three times in relief.

"At the end of the day, we have to be better, no matter what the circumstances are," Pipkins said. "That's biggest thing we all know, it wasn't our standard. We just have to be better."

Down 20-10, the Bolts had hope to cut into the deficit but Heinicke was sacked on first and third down as the unit went three-and-out.

Right tackle Joe Alt appear to hobble off after the third-down play. The Chargers didn't get the ball back after a punt.

"Wish we could've given him a little bit more time there to operate," Harbaugh said.

Pipkins added: "I think it was just a lot of moving pieces. We just got to be able to roll with the punches and do what we need to do no matter what the circumstances are."

5. Miscues on special teams

In a game where points and yards would be at a premium, the Chargers weren't helped in the third phase on Sunday.

The Chargers punted on their opening possession and appeared to pin the Steelers at their own 5-yard line. But an illegal formation call on Stone Smartt meant the Bolts had to re-kick it. Instead, Pittsburgh started at its own 21.

The Steelers then kicked off early in the second half, with the ball bouncing in the landing zone. But Derius Davis couldn't field the ball cleanly as he was smothered at the 12 for only a 14-yard return.

A few plays later, J.K. Scott's punt went just 39 yards as Deane Leonard was called for a 5-yard penalty for voluntarily running out of bounds.

On a day when the Bolts needed the be at their best to stay undefeated, they came up short in a hostile environment.

"Give credit to the Steelers in all three phases there at the end," Harbaugh said.