MINNEAPOLIS — Kirk Cousins had started all but two games in his six seasons for Minnesota, giving the Vikings rare continuity at quarterback before he went down in October with a season-ending Achilles tendon tear.

On their fourth starting quarterback of the season, the Vikings are discovering the harsh reality of life without Cousins, the four-time Pro Bowl player who is already third in team history in passing yards.

While Joshua Dobbs’ sudden emergence provided a temporary solution, the swinging door at quarterback now has Minnesota out of playoff position in the NFC. Nick Mullens threw for 411 yards and two touchdowns but also had four interceptions — and two fumbles the Vikings recovered — in the 30-24 loss to Detroit on Sunday.

“I thought he was aggressive with his arm,” Minnesota coach Kevin O’Connell said. “There were some opportunities that, even on some of those turnovers that happened, I thought there was some potential grass to maybe throw the ball away from defenders, things like that. But I thought Nick battled.”

Mullens, in his second season as the primary backup to Cousins, was out with a back injury when Cousins went down. Mullens replaced Dobbs, who was acquired in an emergency trade on Oct. 31, in the fourth quarter on Dec. 10 and helped secure a 3-0 win against Las Vegas. But Mullens has six turnovers in the past two games, both losses that dropped them to 7-8. They have lost four of their past five games.

He was intercepted at the 5-yard line by Ifeatu Melifonwu with 49 seconds left as the Lions sealed the victory and clinched the NFC North title.

Mullens wasn’t dismayed by his performance.

“Personally, I think I just have to take the next step,” Mullens said. “I believe that I’m a very good quarterback, but what’s it going to take to take the next step?

“The NFL is a mental game. It’s you versus you. That’s what I just keep striving for. It’s hard work, execution, trust the guys around me.”

Mullens was working with a depleted receiver group down the stretch as tight end T.J. Hockenson (knee) and rookie receiver Jordan Addison (ankle) left the game with injuries and didn’t return.

Add in Mullens as the latest starter on the quarterback carousel — rookie Jaren Hall started the game after Cousins’ injury only to leave early with a concussion — and the Vikings have been lacking their usual rhythm in the passing game.

“I really do think it goes to show the rest of the world the type of player that Kirk is,” said star receiver Justin Jefferson, who had six catches for 141 yards. “At the end of the day, this is a tough league. Not everybody is meant for this job, you know?”

Cousins attended his first home game since the injury and helped hype up Jefferson before the announcements for the starting lineup. Jefferson knows the Vikings are missing him and need more time with Mullens, who had a number of passes arrive late to receivers.

“It’s tough not having ‘8’ out there, the captain that he is, the leader that he is,” Jefferson said. “He’s a great player. Nothing taken away from Nick. Nick is an outstanding player as well. We just need to build on that confidence that we have. We just need to go on that practice field and make sure that we’re getting all the timing right, making sure the ball is where it needs to be.”

Mullens believes ball placement was the issue on Sunday.

“I believe I’m very accurate quarterback,” Mullens said, adding: “Decisions, accuracy, you have to be elite at all times. I’ve done a good job making plays and moving the offense. We’ve worked really hard, collectively, to move the offense. Just you have to you avoid those mistakes.”