(Courtesy Lucian Mattia.)

“I spotted him while I was playing third,” said Mattia, whose video was featured on ESPN and every sports Web site in the world on Tuesday. We even talked about it on Post Sports Live. “I was yelling at him to come play catcher for us.”

Mattia said Harper later told him he was a slow-pitch softball novice; “I think you’ll do all right,” the Nats fan said.

And Mattia assured me that, despite some negative comments about Harper seeking attention, that’s now how it happened.

“He didn’t roll up looking to steal the show or cut in the middle of our game,” he said. “It was a total treat.”

As for his whiff and harmless fly?

“I’ll stack him up against whoever else at softball if he ever wants to take another crack at it,” Mattia told me.

Although Mattia did follow up with a double that likely would have scored Harper had he taken first base.