The slide in NFL ratings could be as much a trend as a blip.

The presidential campaign, the growing move away from cable, the increase in live streaming sports and competition from compelling baseball have all been given as reasons for a double-digit decline in viewership through the first five weeks.

All legitimate explanations, experts say. But one of the main selling points of live sports to the networks – they’re appointment viewing that most people don’t like to record and watch later – could be eroding, as the fan base fragments, even for America’s most popular sport.

“It’s not to say that less than the majority of people are going to sit down and watch the game at a certain time,” said Dennis Deninger, who teaches sports management and sports media courses at Syracuse. “It’s just to say it’s retreating, and that retreat puts into question the value that’s been attached to TV rights that were locked up for the long-term.”

According to Sports Media Watch, viewership for last week’s games was down 26 percent for Monday night, 15 percent for Sunday night (against the second presidential debate) and 20 percent for Thursday night. Overall, for the first four weeks of the season, ratings across the league were down 11 percent.

The decline was concerning enough that league executives recently sent an internal memo to the NFL media committee, comparing this year’s slide to a lesser decline during the 2000 election cycle and conceding that, “While our partners, like us, would have liked to see higher ratings, they remain confident in the NFL and unconcerned about a long-term issue.”

The current TV contracts, worth between $8.5 billion to more than $15 billion each, expire in 2021 and 2022. What the networks are willing to pay when it’s time to renegotiate will be the best indicator of how big an impact America’s changing viewing habits have had on the NFL, and whether pro football remains the nation’s undisputed entertainment king.

But there’s still a lot of uncertainty over how new technology will impact viewership. Best example: Yes, you can live stream Thursday night games on Twitter, but what if your connection is shaky?

And how much better will that connection get over the next five years?

“There will be some instances where the composition of (the media deals) will change vastly, and others where they’ll continue to engage with traditional partners,” said Adam Jones, the director of PwC Sports Advisory Services.

“All the deals may not yield the same premiums. But we could see a shift in the actual structures of the deals, from traditional rights fees to a smaller base” with more digital-based bonuses and incentives on the back end.

PANTHERS: Cam Newton has been cleared from the NFL’s concussion program and can play Sunday when Carolina visits New Orleans.

Previously, Panthers Coach Ron Rivera said the quarterback and 2015 league MVP was expected to start against the Saints “barring a setback.”

Patriots: New England signed defensive linemen Geneo Grissom and Anthony Johnson to the 53-man roster from the practice squad, and placed linebacker Jonathan Freeny and tight end Greg Scruggs on injured reserve. Grissom, 24, is a 6-foot-4, 265-pounder who played in 14 games as a rookie. Johnson, 23, is 6-2, 295 pounds and as a rookie played in seven games with Miami.

Washington: Tight end Jordan Reed will not play in Sunday’s NFC East showdown with Philadelphia.

The team announced Saturday that Reed was downgraded from questionable to out because of a concussion. Reed reported symptoms Tuesday, was diagnosed with the sixth documented concussion of his pro and college career, and did not practice this week.

Reed is Washington’s top offensive target with 33 catches for 316 yards and two touchdowns in five games this season. Vernon Davis and Niles Paul figure to see more action with Reed out against Philadelphia.

Cowboys: Owner and general manager Jerry Jones said there is a chance Dez Bryant plays Sunday at Green Bay.

Bryant returned to practice this week after missing the last two games with a hairline fracture in his right knee.