Generally, pass interference is something that only defensive players have to worry about, but once in a while, you will see the call made on a receiver.

Take Thursday night, for example, when Washington Redskins wide receiver Kelvin Harmon was hit with an offensive pass interference call during the Redskins' preseason game against the Cincinnati Bengals.

Jay Gruden challenged the play, but lost.

Of course, pass interference calls being reviewable is a brand new feature, but it's one that Gruden does not particularly like, as he does not understand why he lost his challenge on Thursday evening.

“I need an explanation for that one,” Gruden said, per Michael David Smith of Pro Football Talk. “I don’t know. All I know is I want Kelvin Harmon to do that every time the ball is in the air. That’s why we drafted him because he’s aggressive when the ball in the air. If he can’t do what he did in this game then I don’t know what he can do. I’m going to continue to coach Kelvin Harmon to go up and go get the ball like he did tonight and good things will happen for him. We’ll get the explanation, hopefully.”

The new rule was instituted as a result of the controversial finish in the NFC Championship Game back in January, when Los Angeles Rams cornerback Nickell Robey-Coleman clearly interfered with New Orleans Saints wide out Tommylee Lewis on a key third-down play in the fourth quarter, but no call was made. The Rams proceeded to win the game, which many feel was largely due to that bad no-call.