The National Football league prefers to focus all attention on what happens between the lines, even when brains are being battered.

So we can be confident that league executives took no pleasure in the confusing mess that was the players’ protest during the national anthems at 14 stadiums today.

The protests were not unexpected. They can be seen as a reaction to the inflammatory remarks Donald Trump made on Friday, when the president suggested that owners peremptorily fire players who signal that they are protesting, during the anthem.

For many in the NFL, it must have seemed as if they were under attack by the president of the United States, and they wanted to react. And it wasn’t just the players. The league sent out a press release criticizing Trump’s statements, and several club owners were on the field for the protests today.

Most players appeared to be protesting, in some way, though it is inaccurate to describe what happened as an expression of unity — as can be seen in the espn.com compilation of the actions of every team.

Some players did not take part in the protest. (The whole of the Carolina Panthers stood during the anthem, same as usual, according to ESPN’s reporter.) Some players took part with half-hearted enthusiasm, like the Kansas City Chiefs players who stood, hand over heart, but behind the bench, instead of on the sideline.

Of those who protested, it seems as if locked arms was the No. 1 attitude. But others sat on the bench. Some took a knee, a la Colin Kaepernick, the former San Francisco 49er who was the first to kneel during the anthem, a year ago. At least two Broncos stood with clenched fists raised, according to ESPN.

We are left to guess which action was considered the strongest protest.

Many fans at the stadiums booed the players, and fan opprobrium is never good — those are the people who get everyone paid.

One former New England Patriots lineman, Matt Light, said it was “the first time I’ve been ashamed to be a Patriot” and said he was sure he wasn’t the only former player to feel that way.

So, let’s assume the NFL would prefer not to have a repeat of what happened on Week 3.

Here is what the league should do, and it is a solution that already has been tested.

The NFL can thank three clubs for providing an example of how to handle the desire to protest.

When the anthem was played, the Pittsburgh Steelers, Seattle Seahawks and Tennessee Titans were not on the field.

They were back in the clubhouse.

Instead of stirring up bad feelings out on the field, they let their absence speak for them.

It certainly got across the idea that they were not happy — but it did so without the in-your-face repudiation of the anthem that so disturbs many fans.

If players want to continue protesting during the anthem this week, the NFL should recommend that all 32 teams simply stay in the lockerroom.

When the anthem is over, players then head to the field. They can walk out on the field with arms interlocked, if they prefer. The key is not making a scene on the field during the anthem.

Going that direction would have additional benefits, for players.

–It produces true unity in the teams. They all would be behaving in the same way and doing it together. What we saw today was players behaving in a dozen ways, and we can safely assume players noticed which of their teammates did what — and will be tempted to judge each other, one way or another.

–Speaking of judging, the players’ employers are watching, too. But if the whole team is out of sight …

–Staying inside during the anthem also likely would chill out some of the fans who were booing — because absence is far less provocative.

The league could make clear that teams can skip the anthem as long as they want. And each team could decide how long they want to do it. For another week, another month — until the end of Trump’s presidency.

Second, as I have suggested before, the NFL — and all U.S. sports organizations — should stop performing the national anthem before games.

Really, what has the anthem got to do with sports?

Before World War II, American sports teams apparently rarely played the anthem before games. Somehow, Babe Ruth and Honus Wagner and Jim Thorpe got by, and so did the fans.

When you get down to it, the anthem can be divisive — and in many ways the players did not broach.

Some anthem listeners are zealots about behavior. Everyone’s. No hats! Hand over heart! No eating! No drinking! No talking!

Others cringe at the thought of another bad performance of a difficult song, or another singer forgetting the words.

So much can go wrong.

We all know, I like to believe, that club sports go on all over the world without a national anthem before the game.

I am not aware of a soccer league in Europe that plays a national anthem ahead of club games. And why should they?

What they do is line up and walk out, one team of 11 on either side of the game officials, and after a few seconds one line of player passes the other line, shaking hands as they go.

No anthems. It works just fine.

This is the long-term solution. But we cannot expect American sports to figure it out immediately. Some will suggest it is somehow anti-American.

In the interim, the NFL should take a cue from the Steelers and Seahawks and Titans: Protest by staying in the lockerroom. Message received and a lot of people not as angry.