San Francisco 49ers coach Jim Harbaugh isn't happy with how the NFL is interpreting legal hits on quarterbacks running the read-option.

He called the NFL's ruling "flawed and a bit biased."

In a rules video, NFL vice president of officiating Dean Blandino reviewed read-option plays and says the quarterback while in the act of running the read-option can be hit.

"The quarterback can be hit like a runner until he's clearly out of the play," Blandino said in the video.

A fired-up Harbaugh took issue with the ruling.

"I believe that when a quarterback is handing a ball off or faking a ball -- in the read-option case, he's reading on an option play and he's as defenseless as a quarterback who's in the act of throwing. I know what the rules are, I know how they’ve been explained, but there’s still some gray area. When you start using words like ‘clearly’ — he clearly doesn’t have the ball — what does that really mean? I just handed off, I don’t have the ball, he’s got the ball, put your hands up? There’s a bit of a gray area there. To me, he’s a quarterback until he leaves the pocket as a running threat. I think it’s flawed, the way they’ve got it now.”

What Harbaugh has an issue with is the possibility that star quarterback Colin Kaepernick could be injured.

“Treat him like a running back?” Harbaugh said. “You’re opening a license to hit him outside the strike zone. I’m entitled to my opinion, that’s why I answered the question. I think it’s flawed and I think it’s biased.”

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Aaron Wilson covers the Ravens for The Baltimore Sun