As the Vikings prepare for Sunday's game with Detroit at Mall of America Field, we asked Dave Birkett, the Lions beat writer for the Detroit Free Press, to give us his up-close-and-personal scouting report. Here are four things you need to know …
1) The Lions are back in the playoff hunt.
When the Vikings left Ford Field on Sept. 30 with a 20-13 win, Detroit had fallen to 1-3 and looked to be in danger of becoming an afterthought in the NFC playoff race. But then came a much-needed Week 5 bye. And the Lions have now clawed back to .500 thanks to solid road wins over the Eagles and Jaguars plus an impressive rally to beat the Seahawks in Week 8.

Now, Birkett said, comes a critical three-game stretch that should make clear the direction the Lions are pointed by the time they lay down to rest on Thanksgiving night. Following this week's game in the Twin Cities, the Lions return home to play Green Bay on Nov. 18 and Houston four days later.

"This three-game stretch here will ultimately decide whether they're playoff material or not," Birkett said. "They need at least two wins in this stretch."

For Detroit, the late-season schedule is hard to decipher. They'll play five of their final seven games at home. So that's a bonus. But three of those home contests come against the teams with the best records in the NFL right now – Houston, Atlanta and Chicago. And of the teams left on the Lions' schedule, the Cardinals are the only ones without a winning record right now.

"I think there's still some uncertainty about what the Lions are," Birkett said. "Not to downplay the wins over Philadelphia and Seattle. But we'll get a much clearer picture of things the next three weeks."

2) The Lions special teams have improved dramatically since they last met the Vikings.
Remember Percy Harvin's 105-yard kickoff return touchdown to open the game in Week 4? What about Marcus Sherels' 77-yard punt return score early in the third quarter? Those were the third and fourth return TDs allowed by the Lions coverage units in a span of seven quarters. It's no wonder special teams coordinator Danny Crossman was under such heat in Detroit as the calendar flipped to October.

But the Lions have addressed their issues and improved on special teams. Since Week 6, they've allowed only two kickoff returns past the 30 and have held punt returners to an average of 6.0 yards per attempt.

"They've definitely improved without a whole lot of changes," Birkett said. "There have been a few minor tweaks to the coverage units but not much. It's been more attention to detail. And part of it also is that the offense has played considerably better, which has helped field position."

3) Receiver Calvin Johnson is hurt and quarterback Matthew Stafford is hot right now.
Believe it or not, Stafford and Johnson have yet to connect on a touchdown pass this season after hooking up for scores 16 times in 2011. Johnson's lone TD this season was a 3-yard grab from Shaun Hill late in an overtime loss to Tennessee on Sept. 23.

So is the All-Pro receiver dealing with the infamous Madden curse, suddenly beat up as a result of being on the front cover of a video game?

"Calvin says he's a God-fearing man and doesn't believe in curses," Birkett said. "But he's definitely had more than his fair share of bumps and bruises this year."

The curse would be easier to laugh off if Johnson didn't have a sore knee that may cause him to miss all of practice for the second consecutive week. The knee issue comes after Johnson has already dealt with injuries this season to his finger, foot and head.

Still, he ranks 10th in the NFL in catches (48) and third in receiving yards (767). He had seven catches for 129 yards last week against the Jaguars and wasn't even himself because of the knee pain.

"He was definitely limited last week," Birkett said. "You could see that he couldn't cut off that left knee really well. The Lions tailored some of their routes around that. And when they sent Calvin on a deep ball, they were sitting him out the next snap so he wasn't beating on that knee too much."

As for Stafford, he's coming off two red hot games in wins over Seattle and Jacksonville. The stats in those games: 56-for-82, 637 yards, three TDs, one interception. More impressive, Stafford has completed 23 of his 27 third-down passing attempts and has spread the ball around to nine receivers.

"Stafford is the number one reason to believe the Lions' turnaround is legit," Birkett said. "Early on, I think it just took him a little time to adjust to how defenses were playing him and taking away Calvin Johnson. But these last few weeks, he's been great on third downs. He's been more accurate and efficient. And the offensive line is playing well up front."

4) The Lions secondary remains vulnerable.
Yes, Detroit will do everything it can to stack the box against Adrian Peterson. But they have still yet to find stability in the secondary, having started a different defensive back combination in every game this season.

Safety Louis Delmas is in danger of missing his sixth game this season as he continues dealing with a nagging knee injury. Detroit's starters last week against the Jaguars were Chris Houston and Jacob Lacey at cornerback and Erik Coleman and Ricardo Silva at safety.

"Delmas is really the glue of the defense back there," Birkett said. "And they're noticeably weaker without him."

Still, Detroit has a top 10 passing defense right now. And naturally, they're more concerned with stopping Peterson than they are worried about the Vikings' sputtering passing attack.