San Francisco 49ers defensive coordinator Steve Wilks on Friday revealed the harsh reality about the team’s defense against the Detroit Lions in the NFC Championship.

Niners head coach Kyle Shanahan, linebacker Fred Warner and defensive end Nick Bosa attributed the issues to pursuit and effort. San Francisco went down 24-7 at halftime before putting on a thrilling comeback to win the game and advance to Super Bowl LVIII.

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Wilks was asked what he attributed the issues to.

"Collectively as a team, I can tell you as a defense it's unacceptable," Wilks said.. "Alright. We talked about that. I wish I could tell these guys on play four, on play 27, this is what's going to happen. You don't know. 

"So, we’ve got to make sure that we play every down as if it's going to be the difference in the ball game. And you could see on those particular plays, it wasn't to our standard. Those guys understand and know that and, quite honestly, it was embarrassing."

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Shanahan pointed to some issues during the game earlier in the week.

"They were expecting someone else to make the tackle," he said, via ESPN. "Whenever you're expecting someone else to make the tackle, bad things happen."

Niners general manager John Lynch made clear that effort was "nonnegotiable." He said questions around effort on the field were addressed with players.

Bosa eventually got to Lions quarterback Jared Goff twice. The team also forced a Jahmyr Gibbs fumble, which was recovered by Arik Armstead.

The defense will have to buckle down against the Chiefs next weekend.

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