The two most obvious areas were their performance in the red zone and penalties.
Minnesota's offense entered the game ranked eighth in the red zone, converting 33 attempts inside the 20-yard line into 20 touchdowns (60.1 percent) over their first eight games. Against the Lions on Sunday, they were only two for six. One was a fumble by Adrian Peterson, another was a botched pitched between Peterson and Percy Harvin and another was a failed run by Jeff Dugan on fourth-and-1. The other red zone attempt that didn't turn into a touchdown was a field goal on the first possession of the game.
"(We took a) step back a little bit in the red zone, just by virtue of the fact that we had one on downs, we had a fumble down there, we had a field goal down there," Vikings coach Brad Childress said. "I think they counted Adrian's fumble going in as a red zone deal, because I think they probably credit the fumble around the 20-yard line. So we need to tie that down, because those things always come back and bite you when you can't get those seven-point efforts in there."
Childress said he will talk with Peterson about his fumble at the 18-yard line, when he was caught from behind by CB Philip Buchanon, but he also indicated that he doesn't want his playmakers running in the open field with their heads turned back the whole time.
"You've never seen any sprinters that are sprinting and they cock their neck and really maintain their speed," he said. "Generally we tell wide receivers that if you put your chin on your shoulder you usually cut your speed by a quarter when that happens. So it's a coaching point."
While most people probably figured the Vikings would hand the ball off to Peterson when they were facing fourth-and-1 on the 8-yard line in the second quarter, they elected to go with a quick dive to the right with Jeff Dugan.
The fullback/tight end was stuffed for no gain and the Vikings had to settle for a 10-0 lead at the time.
"I just didn't like the execution," Childress said when asked if he was grimacing after the play. "I didn't like the penetration. That will typically stop plays like that. Brett is not a great sneaker so we weren't going there. I didn't like the result either."
Childress wasn't second-guessing the play call.
"Obviously you have something in your game plan that's on your card and that's the way you're seeing it," he said. "You make enough of those decisions, some are going to end up right and some are going to end up where you get stopped. You stick by it. I'm sure that Adrian would have to liked (the ball) in that situation, but it was six inches and that was our six-inches call."
The Vikings also entered the game as the fifth-least penalized team in the league with 41 penalties over eight games, but they added 13 to their total on Sunday. Some of the calls Childress didn't agree with and he has voiced his opinion to the league, but he called the total number of penalties on Sunday an anomaly.
"Absolutely. The pre-snap ones, they're ours. The other ones, some of them are there and one of the other ones got called," he said. "Those I have a question about. If they get played, it's like a card laid is a card played. When the flag is down there and they're calling it, we have to deal with it. Not happy about it, get it corrected. It raised its ugly head so we have to address it and look at it and clean up your own backyard."
But in a 27-10 win, it can't be all bad, no matter the opponent. The Vikings entered the game with a league-leading 31 sacks, four sacks more than any other team, twice as many as a number of teams and almost four times the amount that Jacksonville had. Against Detroit, they managed three sacks but were credited with 13 quarterback hurries.
"Defensively, I thought they did a great job of hitting the quarterback, and anytime you can do that, you make a guy move his feet," Childress said. "I don't care if he's a first-year guy or a 10th-year guy, anytime you can make him trick his feet in the pocket, he's not going to be as accurate as he'd like to be."
Ray Edwards led the way with two sacks and four hurries, with Childress calling Edwards "outstanding."
Offensively, the Vikings had a very productive and balance attack. They produced 492 yards of offense, with Sidney Rice getting 201 yards receiving and Adrian Peterson gaining 133 yards on the ground.
Despite the mistakes, the Vikings were still 17-point winners, and that was a rarity through Sunday's Week 10 games, when 11 of the 14 games were decided by 10 points or fewer and seven by six or fewer.