SANTA CLARA, Calif. -- Nick Bosa's first unnecessary roughness penalty as a pro raised eyebrows, caused a concussion and, at least to the 49ers' opponents, looked like a cheap shot.
Coach Kyle Shanahan vehemently disagrees with the "cheap shot" accusation, and he has a strong case.
What happened was Bosa launched his left shoulder into an unsuspecting Brian O'Neill, the Minnesota Vikings right tackle, during Richard Sherman's interception return about five minutes after halftime of Saturday's 27-10 divisional-playoff win.
"People say 'cheap shot' when someone gets hit violently," Shanahan began Monday in Bosa's defense. "To me, the term 'cheap shot' is your intent is to try and hurt someone. I don't think he's thinking about that at all.
"That's a normal block in football for a long time. The guy wasn't completely out of the play, he could have made a tackle and Bosa went and hit him. That's a rule, you can't do that now, you can't hit a guy in that position."
So what could Bosa have done differently?
"You basically have to set a screen, which means let him hit you and just take it," Shanahan said. "That's part of this game, that's what you have to do and that's we will coach him up on to do, because you will get a penalty (otherwise).
"To call it a cheap shot, that means you're trying to hurt someone and I know that wasn't the case."
O'Neill got hit near his right shoulder and chest, not directly to his head. He was diagnosed with a concussion and did not return to the game. The 49ers scored 10 unanswered points and advanced to Sunday's NFC Championship Game against the Green Bay Packers at Levi's Stadium.
Vikings coach Mike Zimmer said he didn't see Bosa's hit, but added: "I just heard (players mention) it was a cheap shot, which I think it was."