JACKSONVILLE, Fla. – For just the second time in his career – and for the first time with the outcome hanging in the balance – Luke Kuechly exited a game early.
While A.J. Klein was concerned for his fellow linebacker when he suffered a concussion in Sunday's season opener at Jacksonville, Klein sounded unconcerned about the tall task of replacing Kuechly.
"If Luke goes down, I go in," Klein said. "It's as simple as that."
Despite Klein's matter-of-fact approach, the fact of the matter is that no one can simply replace Kuechly, a player with two NFL tackle titles and one NFL Defensive Player of the Year trophy through his first three pro seasons.
Or maybe it is that simple after all - with a little help from your friends.
"This game is a team game. Every single position stepped up," said Klein, who played in place of Keuchly the entire second half and helped the defense put the clamps down in a 20-9 victory. "There can't be a drop-off. Everybody has got to be ready and prepared to play."
Kuechly, who appeared to be fine after the game but who must go through the NFL's concussion protocol leading up to next Sunday's home opener, suffered the injury with less than a minute left in the first half while bringing down running back T.J. Yeldon in the open field.
Klein, a third-year pro with starting experience but not in Kuechly's spot in the middle, came in and recorded the tackle on the next play, but the Jaguars went on to reach the end zone and pull within 10-9 at the break.
At halftime, though, the defense had a chance to collect itself.
"They talked about rallying around each other, talked about stepping up," head coach Ron Rivera said. "When something like that happens, that's what has to happen. You can't sit there and go, 'Woe is me.' You have to do your job and do it better."
Linebacker Thomas Davis was among the most vocal players in the locker room.
"It's tough whenever you lose one of your best players on defense, but it's a challenge to the rest of the guys out there. We have to step our game up and take it to another level," Davis said. "It was all about playing up to our standards, about playing up to the level we're capable of playing and trying to accomplish what we want to do defensively. That's what it boiled down to."
Kuechly also felt well enough to tell the defense to keep working before he exited the field prior to halftime, and what happened in the second half no doubt made him feel better.
After Jacksonville managed 190 yards in the first half and the Panthers' lone sack came courtesy of Kuechly, the Panthers turned up the heat after halftime. The Jaguars totaled just 75 yards, and quarterback Blake Bortles tossed two interceptions and was sacked four times.
"Each time we take that field, it's an opportunity to prove ourselves," said Davis, who recorded one of the interceptions and one of the sacks to help Carolina shut out Jacksonville in the second half. "I think we did a really good job of responding and coming out in the second half and playing Panthers defense."
It was unusual to have to do it without Kuechly, whose only other missed time of any significance came after his unwarranted ejection in a blowout loss at Green Bay last season.
Klein, potentially pushed down the rotation by Carolina's selection of linebacker Shaq Thompson in the first round of the 2015 draft, answered the call. He saw just three defensive snaps before Kuechly's injury but then rotated with Thompson and nickel cornerback Bene Benwikere the rest of the way and finished with six tackles.
That was one behind Davis – and Kuechly – for the team lead.
"A.J. did an amazing job," Davis said. "When the opportunity presented itself, he had to step up, and he had to play a big role. He had to replace Luke, and he did a tremendous job."
View game action photos from Carolina's 20-9 win over Jacksonville.

Jacksonville Jaguars quarterback Blake Bortles (5) looks for a receiver as Carolina Panthers defensive end Mario Addison (97) puts on pressure during the first half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/John Raoux)

Carolina Panthers quarterback Cam Newton (1) throws a pass against the Jacksonville Jaguars during the first half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/John Raoux)

Jacksonville Jaguars head coach Gus Bradley argues a call with line judge Mark Steinkerchner (84) during the first half of an NFL football game against the Carolina Panthers, Sunday, Sept. 13, 2015, in Jacksonville, Fla. (AP Photo/Stephen B. Morton)

Jacksonville Jaguars defensive back Sergio Brown, right, stops Carolina Panthers tight end Greg Olsen, left, after a reception during the first half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/John Raoux)

Jacksonville Jaguars defensive end Chris Clemons (91) sacks Carolina Panthers quarterback Cam Newton (1) during the first half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/John Raoux)

Carolina Panthers quarterback Cam Newton (1) runs for yardage between Jacksonville Jaguars defensive tackle Jared Odrick, left, and outside linebacker Telvin Smith (50) during the first half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/John Raoux)

Carolina Panthers head coach Ron Rivera disputes a call by officials during the first half of an NFL football game against the Jacksonville Jaguars in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/Phelan M. Ebenhack)

Jacksonville Jaguars middle linebacker Paul Posluszny (51) celebrates an interception against the Carolina Panthers with teammates, including Sergio Brown (38) and cornerback Aaron Colvin (22), during the first half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/John Raoux)

Carolina Panthers wide receiver Ted Ginn (19) makes a catch in front of Jacksonville Jaguars outside linebacker Telvin Smith, left, during the first half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/Stephen B. Morton)

Carolina Panthers fullback Mike Tolbert (35) makes a moves to get around Jacksonville Jaguars linebacker Dan Skuta (55) during the first half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/Phelan M. Ebenhack)

Jacksonville Jaguars wide receiver Rashad Greene (13) scores a touchdown on a 1-yard pass as he gets between Carolina Panthers cornerbacks Josh Norman, left, and Bene' Benwikere, right, during the first half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/John Raoux)

Jacksonville Jaguars quarterback Blake Bortles (5) is stopped by Carolina Panthers defensive tackle Dwan Edwards (92) and defensive end Mario Addison (97) during the second half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/Stephen B. Morton)

Carolina Panthers cornerback Josh Norman (24) runs back an interception against the Jacksonville Jaguars for a 30-yard touchdown during the second half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/Phelan M. Ebenhack)

Carolina Panthers defensive back Charles Tillman, right, breaks up a pass intended for Jacksonville Jaguars wide receiver Allen Hurns (88) during the second half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. (AP Photo/Stephen B. Morton)

Carolina Panthers quarterback Cam Newton (1) is tackled by Jacksonville Jaguars outside linebacker Telvin Smith (50) and defensive tackle Jared Odrick, bottom, during the second half of an NFL football game in Jacksonville, Fla., Sunday, Sept. 13, 2015. Carolina won 20-9. (AP Photo/Phelan M. Ebenhack)