The Vikings' passing attack has been as prolific as promised, but some consistent issues are holding the team back from being among the highest-scoring offenses.

Quarterback Kirk Cousins leads the NFL with 1,075 passing yards. Receiver Justin Jefferson's 458 receiving yards ties Wes Welker (2011) for most in the first three games to begin an NFL season.

Yet the Vikings are averaging 23 points per game after falling 28-24 to the Chargers on Sunday.

Some problem areas — third downs and the red zone — returned after the Vikings offense had middling results in both spots during the Week 1 loss to the Buccaneers. They also had two more turnovers for a league-leading nine turnovers in three games, plus seven penalties on offense.

Asked about third-down woes (converting only four of 14), head coach Kevin O'Connell pointed to protection.

"They were able to get to him a little bit on some of those downs," O'Connell said. "We had Alex Mattison on kind of a designed play against man coverage. He's pretty much by himself at that point, and [Joey] Bosa, I think, off the right side hit Kirk's arm as he goes to throw it. Those are the little things here and there."

Cousins, who completed 32 of 50 passes for 367 yards, three touchdowns and one interception, passed Tommy Kramer for second in franchise history with 162 passing touchdowns. He also took 13 hits (four sacks) from the Chargers defense.

"Just got to find a way to continue to protect," O'Connell said, "and what that looks like, we'll continue to find the best five guys we can put out there."

The Vikings coach sounded open to changing the offensive line, which is why veteran guard Dalton Risner signed a one-year deal last week. Risner was active as a backup as he continues to get into game shape. He practiced at left and right guard last week.

Left tackle Christian Darrisaw returned from a one-game absence due to an ankle injury. Center Garrett Bradbury went through a pregame test for 25 minutes on his lower back but did not play for the second straight week.

The stat eating at Cousins was the Vikings scoring just one touchdown in four trips inside the Chargers 20-yard line.

"The red zone was the challenge," he said. "If you don't perform in the red zone, that's just going to be tough."

Jefferson had seven catches for 149 yards and a touchdown — falling 1 yard shy of becoming the first player in NFL history with at least 150 yards in three straight games to open a season. But Jefferson was rounding up after the game.

"Just like everybody else, they doubled me and have a safety over the top," Jefferson said. "They were all saying I wasn't going to get 150."

Addison's busy second half

Rookie receiver Jordan Addison caught six passes for 52 yards, but he wants more. That's because all of his production came in the second half. He didn't catch his lone target before halftime, although he did draw a defensive pass interference penalty on Chargers cornerback Michael Davis.

"I feel like I had a rough first half, so that dog was in me in the second half," Addison said. "I was just trying to go get whatever ball came my way."

Addison was targeted on four straight plays in the fourth quarter, converting a third down in the process. What was rough about the first half?

"Not getting open," he said. "I just have to do a better job of getting open, then the targets are going to come my way."

Two rookies debut

Two Vikings rookies — defensive tackle Jaquelin Roy and edge rusher Andre Carter II — were active for their first NFL games on Sunday. Both had immediate roles by subbing off the bench in the first quarter. Carter, an undrafted rookie, entered the game during obvious passing downs. Roy, a fifth-round pick, combined with Jonathan Bullard and Dean Lowry to stop Chargers running back Joshua Kelley on fourth down in the fourth quarter. The stop gave the Vikings possession at the Chargers 24 with less than two minutes remaining.

"Man, it felt good," Roy said. "We had the offense back on with 20 or so yards to go. We thought we had it."

Etc.

• Safety Josh Metellus (shoulder) exited in the fourth quarter. Edge rusher Marcus Davenport (ankle) was inactive for the second time in three weeks. Receiver Trishton Jackson was elevated from the practice squad, replacing receiver Jalen Nailor on special teams. Nailor suffered a hamstring injury in practice and was placed on injured reserve.

• The Chargers made cornerback J.C. Jackson, who signed a five-year, $82 million deal last year, a healthy scratch. Running back Austin Ekeler (ankle) and former Vikings linebacker Eric Kendricks (hamstring) did not play. Receiver Mike Williams (knee) and safety Derwin James (hamstring) left in the second half.

• Former Vikings tight end Kyle Rudolph, who recently announced his retirement, sounded the Gjallarhorn before kickoff.