San Francisco 49ers head coach Kyle Shanahan is defending his rookie defensive end Nick Bosa after Minnesota Vikings head coach Mike Zimmer accused Bosa of a "cheap shot" during an interception return.

During the third quarter of Saturday's Divisional Round playoff game, Richard Sherman intercepted a Kirk Cousins pass and, on the return, Bosa laid a block on Vikings right tackle Brian O'Neill. The offensive lineman did not see Bosa coming, and Bosa was penalized 15 yards for a blindside block. O'Neill left the game to be evaluated for a concussion and did not return.

After the game, several Vikings took exception to the hit.

"There's no reason for that hit in the game these days, especially when you go for someone's head," guard Josh Kline told reporters. "It's just very disappointing that someone would do that. There's no place for that... They put that block (crackback) out for a reason."

Zimmer stated, "I didn't see the hit, I just heard them say it was a cheap shot, which I think it was."

On Monday, Shanahan told reporters he did not think the hit rose to the level of a "cheap shot."

"I think people say 'cheap shot' when somebody gets hit violently and to me 'cheap shot' means your intent is to try to hurt someone," he told reporters. "And 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. It was a guy who could've made the tackle, and Bosa went and hit him. That's a rule. You can't do that right now. You can't hit a guy in that position."

Prior to the start of the 2019 NFL season, the NFL prohibited "blindside blocks" where a player blocks back towards their own goal line. When asked how to block on interception returns or other situations where a player has to work back towards their own goal line, Shanahan likened it to setting a screen in basketball.

"Basically got to set a screen, which means let him hit you and just take it," he said of how to block back towards the goal line under the new rules. "That's part of this game. That's what you got to do. And that's what we'll coach him up to do because you will get a penalty for that. But to say it's a cheap shot means you're trying to hurt someone and stuff, and I know that wasn't the case."

Eric Ting is an SFGATE digital reporter. Email: eric.ting@sfgate.com | Twitter:@_ericting