INGLEWOOD, Calif. -- An apparent face mask on Minnesota Vikings quarterback Sam Darnold went unpenalized late in the fourth quarter Thursday night at SoFi Stadium because no official had a clear view of the play, referee Tra Blake told a pool reporter after the game.

Broadcast replays showed Los Angeles Rams linebacker Byron Young grabbing Darnold's face mask and throwing him to the ground in the end zone for a sack and a safety, giving Los Angeles a commanding 30-20 lead with 1 minute, 46 seconds remaining in the game. The game ended at the same score.

According to NFL officiating fundamentals, the referee has primary responsibility for fouls involving hits on the quarterback.

"The quarterback was facing the opposite direction from me, so I did not have a good look at it," Blake said. "I did not have a look, and I did not see the face mask being pulled, obviously."

Umpire Carl Paganelli had secondary responsibility for making the call. But he was also blocked, according to Blake.

"The umpire had players between him and the quarterback, so he did not get a good look at it," Blake said. "He was blocked out as well. So that was the thing. We did not see it, so we couldn't call it."

The play is not reviewable, according to NFL rules.

Vikings coach Kevin O'Connell said he would not use the missed call as an explanation for losing the game.

"It looked like he got a pretty good amount of face mask there," O'Connell said. "I'm not going to get into the call, or no-call, or all that stuff. I talked to our team, officiating and all that stuff ... for us to talk about that, for us to seek comfort in that, is not how we're going to respond to this. It's just not going to happen. I'm going to do the same thing right now. I really don't have a comment on that. Looked like he got a piece of the face mask, but they didn't think so, so they didn't throw the flag."

Darnold added: "The face mask, it is what it is. I thought we could have done a lot to not put ourselves in the situation that we were in. ... So we've just got to continue to play better and not put ourself in that position to begin with."