NEW YORK — The National Football League is continuing a steady decline in audience, with its fourth week of games having the smallest audience on a weekend when some conservatives called for a boycott because some of its players used the national anthem to protest against police treatment of minorities.

The Nielsen company said Tuesday the weekend’s nationally televised games averaged 13.8 million viewers, down from 14.8 million the week before. Opening week registered 16.3 million viewers and the second week had 15.8 million.

Fox News Channel personality Sean Hannity was among the people who said they would not be watching NFL games. It’s virtually impossible to tell what kind of an impact it had, considering the trend that preceded it. The only prime-time entertainment shows to rank higher last week were CBS’ “The Big Bang Theory” and its spinoff, “Young Sheldon.”

“Did it have an impact?” asked Brent Bozell, head of the conservative Media Research Center. “Yeah, it did. I can guarantee it did with one person — that’s me. Beyond that, I don’t know.”

Bozell said, however, that the MRC’s Facebook post calling for the one-week boycott was seen by nearly 35 million people.

An NFL spokesman, Brian McCarthy, said there was no indication that the boycott had any impact, both on television and in the stands. He noted how viewership in general is down for television, and that there has been great competition with a busy news period.

“NFL games continue to be the most valuable programming for networks and remain incredibly strong,” he said.

The week’s other big media story, the debut of Megyn Kelly on NBC’s “Today” show, attracted an average of 2.51 million viewers, Nielsen said. That’s a 2 percent increase over the same time slot a week earlier. But it’s down 12 percent from the same week a year before, with the decline even steeper — 24 percent — among the youthful demographic that NBC seeks for its news programs.

Because the competing “Live with Kelly and Ryan” is a syndicated show, Nielsen will not have comparable ratings for another week.

Kelly received some rough reviews for her first week, but the viewership numbers will be NBC’s ultimate report card.

CBS, led by its two comedies, was the most popular broadcast network during premiere week for the ninth year in a row. Yet viewership for CBS, ABC, NBC and Fox in prime time last week was down 11 percent from the 2016 premiere week, Nielsen said. Viewership declines aren’t unusual at a time people are increasingly watching TV on their own schedules, but by comparison, the four-network decline between 2015 and 2016 was 5 percent.

Networks will have a clearer picture of how its new programming is doing in coming weeks when time-shifted viewing is added in.

Some network highlights: “Young Sheldon” was the most-watched new comedy since “Two Broke Girls” in 2011. NBC’s feel-good drama “This is Us” returned with its biggest audience ever. And the ABC drama “The Good Doctor” opened with considerable promise.

CBS averaged 9.5 million viewers in prime time last week. NBC had 7.8 million viewers, ABC had 5.8 million, Fox had 3.1 million, Telemundo had 1.4 million, Univision had 1.38 million, ION Television had 1.1 million and the CW had 900,000.

ESPN was the most popular cable network, averaging 3.02 million in prime time. Fox News Channel had 2.23 million, MSNBC had 1.63 million, USA had 1.39 million and HGTV had 1.17 million.

ABC’s “World News Tonight” topped the evening newscasts with an average of 8.2 million. NBC’s “Nightly News” had 7.8 million and “CBS Evening News” had 6.1 million.

For the week of Sept. 25-Oct. 1, the top 10 shows, their networks and viewerships: “The Big Bang Theory,” CBS, 17.66 million; “Young Sheldon,” CBS, 17.22 million; NFL Football: Indianapolis at Seattle, NBC, 16.73 million; NFL Football: Chicago at Green Bay, CBS, 14.61 million; NFL Football: Dallas at Arizona, ESPN, 13.7 million; NFL weather delay, CBS, 13.39 million; “NCIS,” CBS, 13.29 million; “This is Us,” NBC, 12.94 million; “Sunday Night NFL Pre-Kick,” NBC, 12.72 million; “60 Minutes,” CBS, 12.46 million.