Drew Lock insisted the ribs were just fine. His confidence, too.

But this could leave a mark on the psyche: An off-target Lock threw four interceptions as the Denver Broncos fell 37-12 to the Raiders on Sunday in Las Vegas.

It was an altogether forgettable afternoon in which the young QB completed nearly as many throws to Raiders defensive back Jeff Heath (two picks) as to one of his favorite targets, tight end Noah Fant (three catches). Not only that but one of the best catches of the day was turned in by linebacker Nick Kwiatkoski, who made a one-handed snare to put a bow on the win by the Raiders (6-3) with 18 seconds remaining.

“I just didn’t put the ball in our receivers’ hands. I put it in their hands,” Lock said after the offense finished with five turnovers. "There could’ve been some better plays there by me without a doubt.”

Lock's line for the day was far from pretty: 23 of 47 for 257 yards and one score in garbage time. His passer rating was 37.3.

He was hit quite a bit, too. He absorbed one blow from the blindside in the first half that caused him to grimace on his next few tosses.

Aching ribs or not, Lock wasn't about to leave the field. He wanted to see things through as the Broncos dropped to 3-6.

“This organization doesn’t pay me, this fan base doesn’t cheer us on, for me to quit on anything,” said Lock, who's now thrown 10 interceptions over his last five games. "They’ll have to carry me off the field for me to come off. That’s just what it is when you play quarterback. You have bad days. You have good days. You have to limit the bad ones.”

Growing up in Colorado, left guard Dalton Risner can't recall many offensive clunkers like this one — nor does he want to see anything resembling that again.

“Unacceptable. That was an unacceptable performance today,” Risner said. "Plain and simple, we’ve got to be better.”

The Broncos were very much in this game at 10-6 late in the first half. But right before halftime, there was a big change in momentum when Lock's 5-yard TD run was nullified due to a holding call on Fant.

On the next play, Lock threw an interception to Heath.

Simply how the day went.

“Everybody’s fingerprints are on that performance — coaches, players,” Broncos coach Vic Fangio said. "We all have to take a good hard look at it. We haven’t found the right formula yet to be consistent on offense.

“It’s very much of a concern. Obviously, four interceptions, you can’t win turning the ball over that much.”

The sporadic play wasn’t just limited to the offensive side, with the defense giving up four rushing TDs and 203 yards on the ground. There were some special teams breakdowns, too, including one that nearly led to a 60-yard punt return for a score by Hunter Renfrow before it was negated by a penalty.

“Everybody’s probably very disappointed and disgusted by it, that a 10-6 game at halftime can turn out like that. But turnovers will do that to you,” said Fangio, whose team hosts Miami next weekend. “We’ve got to get regrouped and refocused and get our energies and our emotions pointed in the right direction.”

Any lingering concern about Lock's confidence?

“There’s only one way to build it: You’ve got to go back to work and he has to start experiencing good play,” Fangio said. "We have to devise our passing game and our offense, our running game, to where he can be more successful. I see a lot of good throws by him. I see a lot of good catches by our receivers.

"We’ve got to be more consistent and more efficient.”

Late in the game, and with the outcome already a foregone conclusion, Fangio said there wasn't a plan to pull Lock for backup Brett Rypien.

“He’s got to fight through this like most young quarterbacks do at some point in their career," Fangio said. "We’re going to continue to play him.”

NOTES: WR Tim Patrick and Las Vegas defensive back Isaiah Johnson were ejected following a scuffle in the fourth quarter. ... WR DaeSean Hamilton had a 7-yard TD catch with 6:10 remaining. He also had a late fumble.

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