COSTA MESA, Calif. — The most excitement created last March, a week before free agency started, only lasted two games and 12 minutes into the third game.

In week one against the Las Vegas Raiders, Khalil Mack and Joey Bosa had a dominant performance. They sacked Derek Carr a combined 3.5 times, hit him six times, and forced two fumbles.

In week three, everything changed when Bosa went out of the game with a groin injury and didn’t return. They would reunite for the final three games of the season, but it wasn’t the same.

They expect this year to be different.

“I’m probably as close with him as anybody I’ve ever played with,” Bosa explained. “He’s like a big brother, in a way. Having a guy that’s an elite player kind of complements me differently. We obviously have our different styles, but just as a friend and as a person, I’m really happy to have him on the team.”

When the Chargers traded for Mack, it was like Batman and Superman teaming up or Captain America and Iron Man.

That is why they made changes during the offseason.

“Understanding what we want to do on the edges, that was one of the things we’ve kind of batted back-and-forth and talked about it a little bit this year,” Mack said.

Bosa shared with the media last week that he weighed about 250 pounds last year because he felt like he needed to slim down the transition to outside linebacker. After a subpar year, he decided to shoot up to around 270.

“You have to be able to establish power as a rusher, that’s what’s going to make you really, really dangerous,” Chargers head coach Brandon Staley explained. “He has some of the best hands in the NFL, which is kind of what he’s famous for, but to set those hands up, you have to really establish power. It’s going to help you in the run game and in the pass game. He’s feeling as good as he ever has.”

After mentioning that he had gained weight, Bosa shared that his pass-rushing brother had also gained about 20 pounds.

“Man, why is he telling my business?” Mack asked laughing. “He wasn’t supposed to tell anybody that. I was trying to shock some people.”

One player who felt the weight change of Bosa was left tackle Rashawn Slater. Since the pads have come on during camp Slater has had to face them both during one-on-ones.

“I feel a little extra pop with him this year, for sure,” Slater said about Bosa.

One example of the difference was felt by Slater when he faced Mack during an 11-on-11 drill in training camp. The edge rusher bull-rushed him into quarterback Justin Herbert forcing him to make a mistake that safety Alohi Gilman took advantage of in the red zone.

“Both of those guys, their get-offs are as good as ever,” Chargers defensive coordinator Derrick Ansley said. “I was talking to Joey a couple of days ago, and he said that he put on about 20 pounds and is feeling stronger. It’s noticeable once you get up on him. Both of those guys are changing their bodies for a good thing.”

Mack played in all 17 games last season, sacking the opposing quarterback eight times while hitting the opposing quarterback 12 times and forcing two fumbles. He was voted to the Pro Bowl, but the pass rush from the defense wasn’t the same.

Kyle Van Noy and Derwin James added some help, but Bosa was missed.

While special teams take over the field, Mack and Bosa make their way to the end of the field and chat or practice some pass-rushing moves while the other watches and gives advice.

“Just getting to know him, putting the time in on and off the field,” Mack said about his relationship with Bosa. “It’s continued to grow. We’re trying to put something together on the field for y’all for 17 games, at least.”

One of the main reasons why they also put on weight is because, besides pass rushing, they need to be able to set the edge and help support against the run. That has been this team’s weakness for the last two years.

That is an emphasis that Staley and the coaching staff put on during meetings and practice. To be successful this season, they need to stop the run. The edge-rushing duo has taken it seriously.

“I just think I’ll be a much more effective player and pass rush with my power and be able to play the run a little more dirty,” Bosa explained.

They have only played six games together and are still getting used to each other. The Chargers hope this duo can live up to their billing and wreak havoc as the Brothers of Destruction did in the wrestling world.

“The more time that we get together, the better it is going to get,” Bosa said. “I think that we complement each other pretty well with our rush styles. I’m just excited to see how it develops throughout the year. Hopefully, we can start out fast.”