PHOENIX — Now we know why the National Football League hasn’t shown much interest in talking about Deflategate.

Because the National Football League doesn’t know what it’s talking about.

Consider what took place yesterday when the league rolled out a troika of officials to explain to Football America and beyond what’s going on with the Deflategate investigation.

As football fans, you want to know if these games are being played on the level, right? If there’s corruption . . . scandal . . . cheating. You want the guilty parties to be punished. Right?

In that spirit, then, you assume the league is bringing hard evidence to the table in this matter. Right?

Turns out that the evidence is about as hard as those footballs that the league claims are not so hard. And that’s why the Patriots, and by that I mean owner Robert Kraft, coach Bill Belichick and quarterback Tom Brady, are speaking out on this matter in clear, concise language.

They believe the NFL has no case. They’re demanding that the league either put up or shut up.

And Kraft, specifically, is asking for an apology if the league doesn’t come up with the goods.

Pretty tough talk.

And now, let’s shift to the surprised looks on everyone’s faces yesterday when Dean Blandino, the NFL’s vice president of officiating, more or less announced that the league plans on using the “liar, liar pants on fire” approach from “A Few Good Men” if they are to prove that Brady used deflated footballs in the Patriots’ 45-7 victory over the Indianapolis Colts in the AFC Championship Game.

According to Blandino, referees do not bother with logging the PSI level of footballs during the pre-game gauging ritual. Unlike the captain’s log from “Star Trek,” nothing gets put into writing, or posted on a bulletin board somewhere.

What we have, then, is Walt Anderson, who reffed the AFC title game, saying that he did pregame and halftime ball checks, except there’s nothing to corroborate what he came up with.

“They’re not logged, and that’s certainly something that can be a thought (for the future),” Blandino said.

That’s great news for future NFL seasons. But it doesn’t do much good in the here and now with the Patriots preparing for Super Bowl XLIX while simultaneously fending off accusations that they’re a collection of cheaters.

But there’s more: The league also addressed this eligible/ineligible receiver issue that apparently got Baltimore Ravens coach John Harbaugh tied up in knots a couple of weeks back as his team was being swept out of the playoffs by the Patriots.

Bill Vinovich, who refereed the Pats-Baltimore game and will return on Sunday as referee of Super Bowl XLIX, teamed up with Blandino to clear up the matter.

When the Patriots deployed Shane Vereen as an ineligible receiver in the Baltimore game, it was Vinovich who announced, “Do not cover No. 34,” which is Vereen’s number. Yesterday, it was explained that Vinovich will make an announcement and then point at, say, Vereen, and use his arms to make the sign for an incomplete pass.

But he will not speak the words, “Do not cover No. 34.”

So when Vinovich told reporters, “I made the announcement: ‘Do not cover No. 34.’ ”

Blandino added, “Which we won’t do.”

Whereupon Vinovich turned to Blandino and said, “We won’t?”

“No,” said Blandino.

If the National Football League had any sense of humor at all, it would have been pumping calliope music through the room during the press conference.

Which brings us right back to Deflategate. It also brings us back to that magic word “integrity,” which for the NFL has become as hard to define as pneumonoultramicroscopicsilicovolcanoconiosis. (Yes, I looked it up.)

If the NFL has any integrity, or even any pneumonoultramicroscopicsilicovolcanoconiosis, it will drop this investigation and allow the Patriots to concentrate on playing football, not weighing footballs. It’s that simple.

Maybe the Pats did something fishy. Maybe they didn’t. We don’t know. What we do know is that the NFL isn’t up to the task of handling this issue, so it shouldn’t.