The NFL and TV networks are having a big problem.

In case you haven’t been in the loop, one of the bigger topics among sports fans are the NFL's declining TV ratings. People are blaming it on the national anthem controversy.

Thus, it could take a financial toll on the broadcasters that have spent tens of billions dollars for the right to air pro football, investment analysts say.

By looking at the numbers, just for the first weeks of the regular season, ratings for the Sunday night game on 21st Century Fox's (FOXA) Fox Sports have slumped 7 percent from a year ago. NFL viewership at CBS (CBS), the parent company of CBSNews.com, has plunged 17 percent for Sunday match-ups and 8 percent on Thursday.

The audience for NBC's "Sunday Night Football" game broadcast has dropped 4 percent. While ESPN's "Monday Night Football" is bucking the trend, posting a 6 percent gain for the season to date.

"Probably it's a little early to use the word 'worry,' but at this point I think it's something that deserves close attention," said Tuna Amobi, an analyst with CFRA who follows the media sector.

"To have now two consecutive years of declines in NFL ratings -- that is something that begs a lot of questions … and could have significant financial implications for the ratings."

Even though they are in a ratings slump, it should be noted that the NFL remains by far the most popular U.S. sport. Since the start of the season, 17 of the top 20 shows on TV have been NFL games.

"NFL games remain the most valuable programming on television and continue to deliver massive audiences across all windows," NFL spokesman Brian McCarthy said in an email.

Despite the fact that they do have large audiences that advertisers covet must be balanced against the steep price tag of beaming NFL games. The networks, CBS, Comcast, and Fox, have a $27 billion deal with the NFL for the right to broadcast games through 2022.

Some people might know that ESPN reportedly pays $1.9 billion per year for the rights to "Monday Night Football," which is a 73 percent increase over the previous contract. NBC and CBS also signed a $900 million deal in 2016 for the rights to broadcast Thursday night games.

"It's a Catch-22 type situation," Amobi said. Broadcasters "are getting a lot of promotional value from these games, and maybe investors are going to ask more questions the next time these [broadcast rights] renewals come around."