CHARLOTTE, N.C. -- Carolina Panthers owner David Tepper was so mad a few weeks ago that he woke up twice in the middle of the night after the Atlanta Falcons embarrassed his team at home. He was so mad that he spontaneously summoned reporters the next day to make it clear he would not accept long-term mediocrity.

Tepper, who in 2018 paid an NFL-record $2.275 billion to purchase the Panthers, probably had another long night after Sunday’s 29-21 loss to the Washington Redskins.

Among the many things keeping him up after Carolina (5-7) dropped its fourth straight will be whether to keep coach Ron Rivera and/or general manager Marty Hurney in place for the final four games.

At best, it seems likely Tepper will make drastic changes after the season with the Panthers set to miss the playoffs for the third time in four years since reaching Super Bowl 50 in 2015.

Rivera already is being questioned about what might happen.

“I’m not worried about my future," he insisted. “I’m worried about this football team."

But there are reasons for him to be worried:

Mediocrity: There’s no doubt Rivera is a good coach. He took the Panthers to the playoffs three straight years (2013-2015) and three times in four years through 2017. He won the NFL Coach of the Year twice (2013, 2015). He is the winningest coach in team history with a 76-63-1 record. But most of the margin keeping him above .500 was built during a 15-1 2015 season. He’s had only three winning seasons in his eight -- three out of nine if this one doesn’t turn around.

Carolina is 12-16 since Tepper purchased the team, which also doesn’t bode well. That the defense Rivera took over late last season has failed to put seemingly lesser teams away also doesn’t help. That adds up to the mediocrity Tepper mentioned repeatedly during an hourlong session.

Disgruntled fans: Tepper wants to build a domed stadium within the next 10 years to attract events such as the NCAA Final Four and perhaps a Super Bowl. He wants the city of Charlotte to pay for most of it. The large number of empty seats on Sunday and in the past few home games makes it harder to convince fans and lawmakers that this is a good investment. It makes it harder to entice corporate sponsors.

Embarrassing home losses: Carolina now has lost at home to Tampa Bay (5-7), Atlanta (3-9) and Washington (3-9), three of the worst teams in the NFL. That contributes to the empty seats. Tepper didn’t make $12 billion in his business career without paying attention to detail.

Cam Newton: Tepper gave Rivera and Hurney a pass last year when the quarterback’s shoulder injury after a 6-2 start led to a seven-game losing streak. He gave them the offseason to shore up the backup spot in case Newton didn’t recover or was injured again. A Lisfranc injury ended Newton’s season after Week 2, and now there is debate over whether the 2015 NFL MVP should be brought back in 2020 for the final year of his contract -- let alone signed to an extension after that. Kyle Allen has lost four straight after a 4-0 start this season, which clouds his future as a potential starter. If Tepper is convinced it’s time to move on from Newton, which he made clear a few weeks ago was undecided, it might make sense to also start over with a new staff.

Giving up: One of the trademarks of Rivera’s teams early at Carolina was that they played better down the stretch. Last year’s team finished 1-7. This year’s team has lost four straight. And while Rivera insisted players “competed their butts off" on Sunday, the defense gave up a season-high 248 yards rushing to a Washington team averaging 85.9 yards a game. That could be interpreted as giving up, although linebacker Luke Kuechly spoke up for Rivera and the staff afterward. “Coach Rivera does such a great job of keeping us level-headed. He’s done a great job with it since he’s got here, and we’re going to do the same thing moving forward."

Pittsburgh influence: Tepper grew up in Pittsburgh and was a minority owner of the Steelers for nine years before purchasing the Panthers. Tepper saw his hometown team win six Super Bowls since 1972, make the playoffs 29 times and have only six losing seasons. That’s his definition of what success is. And although there are teams that would love to say they went to the Super Bowl twice in the past 16 years, as the Panthers have, the lack of sustained success is what will drive Tepper’s decision.