PHILADELPHIA -- The air was heavy inside the Philadelphia Eagles' postgame interview room -- way beyond what is normal for a Week 2 regular-season loss.

News was circulating that 13th-year defensive end Brandon Graham had likely torn an Achilles and would miss the remainder of the season, and his teammates were taking it hard.

"It's terrible. Probably one of the greatest humans I've had the pleasure of playing with, competing with," offensive tackle Lane Johnson said. "He's really the heartbeat of this team, the way he conducts himself, the way he leads and the way he plays."

"It’s always tough and it was a pretty emotional moment for me to see B.G. limp off the field," defensive tackle Fletcher Cox added. "Me and Brandon have played so much ball together and to see him walk off the field was pretty rough for me."

Coach Nick Sirianni didn't sugarcoat it, calling Graham's loss a "big blow." Graham is not only one of Philadelphia's best players -- he led Philadelphia in sacks (8) and tackles for loss (15) last season -- but also serves as the team's tone-setter. His unwavering optimism and endless energy are infectious and are drawn upon when things get hard during the season.

Graham wasn't the only big injury to come out of Sunday's loss to the San Francisco 49ers. Right guard Brandon Brooks (pectoral) exited in the first half and could miss extended time.

"Not having [Brooks] out there is a tremendous loss for us," Johnson said. "Having him out there might have been the difference between us winning and losing.”

These types of injuries to key players could be difficult for a team to overcome. These three players in particular need to step up in Graham's and Brooks' absences:

DT Fletcher Cox

Cox has long been considered the cornerstone of the defense and one of best linemen in the game. But his production has dipped since his career year in 2018, when he posted 10.5 sacks and 34 QB hits. He has totaled 10 sacks and 19 QB hits over the last two seasons combined. He has been shut out of both categories through two games in 2021.

But Cox, 30, impacts the game in ways that aren't always reflected in the stat sheet. Offensive lines shift his way and often double-team him. Cox has been double-teamed on 26 pass-rush plays in 2021, the most of any Eagles defender. That opens up opportunities for players like Javon Hargrave, who has been on fire (2 sacks, 4 TFL, 4 QB hits) so far this season. But elite linemen draw plenty of attention and still find a way to produce. Cox is making $17 million a year. He needs to get back to being a game-wrecker, while stepping into the middle of the circle as the team's primary leader on defense.

DE Josh Sweat

Speaking of money, the Eagles just inked Sweat, 24, to a three-year, $40 million extension that runs through 2024. He and Hargrave were the defensive standouts of the summer. One teammate after the next predicted a career year for Sweat, pointing to his lightning-quick get-off and added strength. He's flashed those traits early but has no sacks and just one QB hit to this point.

The Eagles entered the season with decent depth at the position with Sweat, Ryan Kerrigan and rookie Tarron Jackson in the rotation along with Graham and Derek Barnett. With Graham out, a primary pass-rusher needs to emerge to account for the loss, and Sweat is the top candidate.

OL Landon Dickerson

Dickerson, the rookie second-round pick out of Alabama, stepped in at right guard when Brooks went down with mixed results.

"I have to go back and watch the film, but I think he adjusted well during the second half," Johnson said. "He’s a massive human being and when he starts figuring it out, he’s so strong and big that I think he can hold his own. I think we could have done a lot better there in the first half, especially on the goal line. We had opportunities to punch it in for touchdowns, and we didn’t. When you play a good team like [San Francisco] that’s the difference between winning and losing.”

Dickerson spent the summer rehabbing from an ACL tear and was only recently given the green light to return to the practice field. This was the first week Johnson got reps with him. The talent is there, but for the offense to function properly, Dickerson will have to prove to be a quick study. Monday night's game against the rival Dallas Cowboys is fast approaching.