For all of the excitement the NFL generated with last weekend’s Divisional Round of the playoffs, the league still drew 23 million fewer viewers than it did a season ago.

Even the Minnesota Vikings’ dramatic last-second victory over the New Orleans Saints on Sunday represented a major Nielsen ratings disappointment as 35.6 million viewers tuned into Fox compared to 48.5 million for last season’s Green Bay Packers-Dallas Cowboys matchup in the same time slot.

The equally exciting Jacksonville Jaguars upset of the Pittsburgh Steelers garnered only 31.4 million viewers compared to a Steelers-Kansas City Chiefs matchup during the same time slot last season, which drew 37.1 million viewers.

Minnesota Vikings wide receiver Stefon Diggs (14) scampers to the end zone for a last second, game winning touchdown during a NFC Divisional Playoff game between the Minnesota Vikings and New Orleans Saints on January 14

Even the top-seeded, defending champion New England Patriots saw their audience decline as 26.7 million watched them beat the visiting Tennessee Titans on Saturday compared to the 29.8 million viewers who watched the Patriots beat the Houston Texans a season ago.

In fact, every single game played during the divisional round represented a decline in ratings. The Philadelphia Eagles’ win over the visiting Atlanta Falcons drew just 27.1 million viewers on Saturday—down from the 28.7 million who watched the Falcons beat the Seattle Seahawks during a similar time slot last season.

That’s a 16 percent downtick overall compared to last year, and this comes after the Wild Card round, which experienced its own 13 percent ratings decline from a season ago.

For the NFL, these ratings represent a 10-year low, according to Outkickthecoverage.com.

There are many theories on why the NFL's ratings are suffering.

Beginning with now-former San Francisco 49ers quarterback Colin Kaepernick in the 2016 NFL preseason, many players generated nationwide controversy peacefully protesting inequality and police violence against minorities by refusing to stand during the national anthem.

Former San Francisco 49ers quarterback Colin Kaepernick (center) started the controversial protests last season by kneeling during the national anthem to protest inequality and police violence against minorities

The NFL has also faced negative press over the ongoing issue with chronic traumatic encephalopathy (CTE) – the long-term degenerative condition linked to head injuries that afflicted a number of deceased football stars. In August, a Boston University study diagnosed CTE in 110 out of 111 deceased former NFL players as part of the biggest ever case series on the disease.

But despite the drop in viewership, 20 of the 30 highest-rated shows and 37 of 50 on television in 2017 were pro football games this season, and both NBC and ESPN had the most-watched shows every week in terms of total audience and in all key male demographics.

NFL commissioner Roger Goodell defended the league's ratings on January 7.

'We always want ratings to go up, but we're 37 of the top 50 shows, which is higher than ever,' Goodell told reporters before the Jacksonville Jaguars' playoff game against the Buffalo Bills on Sunday. 'We're likely to be the No. 1 show on Fox - excuse me, on all of television, the Fox Sunday afternoon game. Sunday night, prime time is for the seventh year in a row the No. 1 show. Thursday Night Football is No. 2.

'I think dominance of the NFL in television is still very clear.'

The NFL's Red Zone cable channel, which takes viewers to different games whenever there is a scoring opportunity, drew an estimated 1 million weekly viewers.

Telvin Smith (No. 50) of the Jacksonville Jaguars reacts after recovering a fumble and returning it for a 50 yard touchdown in the second quarter of Sunday's win in Pittsburgh

Wesley Woodyard (No. 59) of the Tennessee Titans tackles Danny Amendola #80 of the New England Patriots during the AFC Divisional Playoff game at Gillette Stadium on January 13

However, some have suggested that NFL Red Zone may have hurt the league's regular season ratings overall by siphoning viewers away from the NFL's network partners like CBS and Fox.

NBC's 'NFL Sunday Night Football' was the most-watched program in prime time, with 18.2 million viewers this past season. That figure is down from 20.3 million viewers in 2016 and 22.5 million in 2015.

NBC, CBS, Fox and ESPN pay more than $1 billion a year apiece for NFL TV rights, with ESPN spending the most - $1.9 billion for 'Monday Night Football.'

Changing viewing habits are frequently cited as a reason for the falling ratings. Others have pointed to a string of injuries to high-profile players such as Green Bay Packers quarterback Aaron Rodgers, and the anemic performances of large-market teams such as the New York Giants, who finished the year with a 3-13 record.

Some, such as Fox CEO James Murdoch and CBS Sports Chairman Sean McManus have publicly pointed to the proliferation of games, many of which failed to be competitive.

Of course, President Donald Trump has continued to point to the ongoing peaceful player protests as an explanation for the league's diminished ratings.

He might have a point as college football ratings have been particularly strong during bowl season.

Philadelphia Eagles running back Jay Ajayi (No. 36) is upended by Atlanta Falcons defensive end Brooks Reed (No. 50) during the NFC Divisional Playoff game on Saturday

The national championship showdown between Alabama and Georgia drew 28.443 million viewers, making it the second-most watched title game in the four-year-old format of the College Football Playoff.

Alabama beat Georgia in overtime, rallying from 13 points down in the second half before winning with a game-ending touchdown pass . Viewership for the all-Southeastern Conference matchup was up 13 percent from last season's Clemson-Alabama rematch from the season before.

The first CFP championship game between Oregon and Ohio State after the 2014 season drew nearly 34 million viewers, a record for ESPN. This season's CFP semifinals on January 1 and Monday night's championship game averaged more than 26.2 million viewers, up 21 percent from last year.

The double overtime Rose Bowl thriller between Georgia and Oklahoma drew a 14.8 overnight Nielsen rating and average viewership of 27 million, up 39 percent over last season's early semifinal. Georgia beat Oklahoma 54-48 and ESPN said the television rating reached a high of 17.3 in overtime.

The Sugar Bowl between Alabama and Clemson got a 12.5 rating and average viewership of 21.1 million, up 10 percent from last season's second semifinal.

The highlight of the NFL's regular season came on December 17, when the New England Patriots' win over the Pittsburgh Steelers drew a 15.2 Nielsen rating.