Since 2002, the 2015 Kansas City Chiefs are the only team to make the playoffs after a 1-5 start. (Jonathan Bachman/Getty Images)

The Carolina Panthers’ season is over. Maybe not in the literal sense — they still have 12 games to play — but the defending NFC champions are now 1-5 on the season with sole possession of last place in the NFC South. That means you can forget the playoffs: The 2015 Kansas City Chiefs are the only team since 2002, the year the NFL expanded to 32 teams, to qualify for the playoffs after this bad of a start, and we haven’t seen anything from this team that signals a turnaround is on the horizon. In fact, it might get worse for Carolina before it gets any better.

The Panthers’ nearly flawless 2015 season was made possible by having one of the best defenses in the NFL. They held opponents to 1.45 points per drive last season by stopping the run (3.9 yards per carry, No. 7 in NFL) and the pass (5.4 net yards per pass, No. 2) while forcing a league-high 39 turnovers. Heading into Week 6 they were allowing 1.84 points per drive and then the New Orleans Saints scored 41 points on 13 drives (3.2 per drive) en route to a 41-38 victory over Carolina.

Quarterback Drew Brees completed 34 of 49 passes for 465 yards and four touchdowns on Sunday, completing multiple throws to eight different receivers, with Brandin Cooks catching seven of nine targets for 173 yards and an 87-yard touchdown.

Part of the problem was letting cornerback Josh Norman leave via free agency. Since his departure, the Panthers are allowing opposing quarterbacks to post a 95.4 rating against, a huge increase over 2015’s mark of 72.3, roughly the difference between Andy Dalton and Brock Osweiler this season. The team also released corner Bené Benwikere, leaving them dangerously thin at the position with Robert McClain (hamstring) and James Bradberry (turf toe) both battling injury. Third-round pick Daryl Worley left the game against New Orleans in the second half to be evaluated for a concussion.

Carolina’s 7.3 net yards allowed per pass in 2016 puts them in the bottom third of the league (No. 26). According to Football Outsiders’ Defense-adjusted Value Over Average, Carolina’s pass defense has dropped from No. 2 to No. 22 in just one season — its worst ranking since 2011 (No. 26), the year before they drafted Norman.

The Panthers also used to have the best — or one of the best — defensive lines in the NFL, but that, too, has regressed.

After adjusting the sack rate for down, distance and opponent, the Panthers’ rate of 7.1 percent in 2015 has slipped to 6.5 percent this season. Defensive end Mario Addison is doing his part — the game charters at Pro Football Focus rank him No. 22 at the position for his pass-rushing ability — but he has only played 118 snaps and doesn’t have the coaching staff’s trust when they need to stop the run. On the interior, Kawann Short and Star Lotulelei are each graded negatively by PFF for their pass-rush acumen, with Lotulelei ranking No. 49 out of 61 interior lineman playing at least half of their team’s snaps.

The Panthers pressured Brees on just 12 of his 51 drop backs in Week 6, hitting him four times and sacking him once.

It’s so bad not even the return of Cam Newton, who missed Carolina’s previous game with a concussion, can help.

When healthy, Newton hasn’t been great, ranking No. 24 out of 30 passers in ESPN’s Total Quarterback Rating. He did come up big on two plays to tie the game at 38-38 with the Saints —  he scored himself on a designed bootleg and then connected with wide receiver Devin Funchess on the ensuing two-point conversion — and finished the game with 312 yards and two passing touchdowns Sunday, but ultimately couldn’t orchestrate a comeback that saw his team trail by as many as 21 points.

More concerning is that Newton isn’t getting much help from an offensive line continues to struggle to keep its quarterback clean in the pocket.

Heading into Week 6, the Panthers’ offensive line had been assigned seven sacks, seven hits and 39 hurries for the 14th-most total pressures this season. Newton took more big hits in the third quarter while trying to extend passing plays and was harassed by a sub-par Saints defense 18 times, resulting in two sacks, four hits and 12 hurries.

Maybe you didn’t think the Panthers would have another storybook season like they did in 2015, but few thought they would be this bad. And just six games removed from a Super Bowl appearance, FiveThirtyEight’s NFL forecast gives them a nine percent chance at making the playoffs, bolstering the notion their season is done.