The Minnesota Vikings were a surprise playoff team last season. Despite one of the NFL's most anemic passing attacks, the Vikings rode the remarkable performance of running back Adrian Peterson and a late-season winning streak to a playoff berth that was sealed with a Week 17 win over the Green Bay Packers.
The San Francisco 49ers, meanwhile, had a surprise or two of their own last year. A Week 10 concussion suffered by quarterback Alex Smith opened the door for Colin Kaepernick to take over under center. Kaepernick's dual-threat ability added a new dimension to the 49ers offense, and ultimately the team wound up champions of the NFC.
The 49ers are considered a Super Bowl favorite again this year, while many pundits predict a backslide for the Vikings. In advance of their Sunday night matchup on national television, here's a look at some of the biggest storylines we'll be watching at Candlestick Park.
Minnesota Vikings Major Storyline No. 1: Pondering Christian Ponder
As we alluded to in the intro, the Vikings struggled through the air in 2012, ranking 31st in the NFL at just under 172 yards per game.
The team traded away wide receiver Percy Harvin in the offseason but added wideouts Greg Jennings and Cordarrelle Patterson, and the hope was that those additions would help third-year quarterback Christian Ponder take the "next step" this year.
However, Ponder has struggled through two preseason games. Over that stretch, Ponder has completed less than 43 percent of his passes for only 68 yards and an interception. Ponder himself admitted that the offense was "confused" by the hybrid defense the Buffalo Bills used last week according to Chris Brown of the Bills' website.
As Doug Farrar of Sports' Illustrated points out, on several occasions in that game the Bills employed packages that essentially dared Ponder to throw the ball downfield. Ponder either missed seeing the opportunities or didn't feel he could make the throw because he didn't test the Bills.
Odds are the 49ers will load up the box as well, and if Ponder doesn't start making defenses pay by hurting them over the top then the grumbles in the Twin Cities are only going to grow louder that Ponder isn't the answer for the Vikings at quarterback.
Minnesota Vikings Major Storyline No. 2: Questions at Linebacker
When the Minnesota Vikings signed free agent Desmond Bishop after he was cut by the Green Bay Packers in June, many pundits pointed to the Vikings' linebacker corps as a potential strength on defense this year.
So far, that hasn't borne out on the field. Bishop has continued to struggle with injuries, and a player who many expected to start at middle linebacker is now fighting for a roster spot.
Bishop played with the second team against the Bills, and although he notched a sack, the 29-year-old also missed a few tackles and admitted to Ben Goessling of ESPN that he needs to be "more efficient" on the field.
Bishop will see his most extensive playing time since joining the Vikings on Sunday, lining up on the weak side next to Erin Henderson. A strong showing from Bishop would likely cement his roster spot and could go a long way towards alleviating concerns about the second level of the Minnesota defense.
San Francisco 49ers Major Storyline No. 1: The Hole at Wide Receiver
After a phenomenal second half of the 2012 season, Michael Crabtree appeared set to ascend to the elite ranks at his position this year. However, a torn Achilles has put Crabtree's entire 2013 season in doubt and raised the question of who will step up opposite newcomer Anquan Boldin at wideout.
So far that question has yet to be answered. 2012 first-round pick A.J. Jenkins did such a bang-up job that the 49ers traded him to the Chiefs last week for Jonathan Baldwin. ESPN reports that Mario Manningham will begin the season on the PUP list as he continues to recover from last year's ACL tear. Free-agent signee Austin Collie has failed to impress. Rookie Quinton Patton is talented but raw and has been banged up in camp.
Baldwin, a first-round pick of the Chiefs in 2011, will see his first game action with the 49ers Sunday in what general manger Trent Baalke called "a great opportunity for a new beginning" after trading for the youngster according to Tom Pelissero of USA Today.
The starting job opposite Boldin is there for the taking, and the 49ers badly need Baldwin to take it.
San Francisco 49ers Major Storyline No. 2: Watch that Hangover
Frankly, outside of the 49ers glaring deficiency at wideout, this isn't a roster with a lot of holes. There aren't any heated position battles raging, at least not among the starters. This game is about getting ready to host the Green Bay Packers in Week 1.
How far will the 49ers advance in 2013?
In that respect, the Vikings aren't a very good tune-up. If there's a question on defense it's in the 49ers revamped secondary, but the odds of Ponder testing that secondary are about the same as the odds of a member of the cast of Jersey Shore earning a master's degree in quantum physics.
However, a storyline that will probably dog the 49ers all season long is talk of the dreaded "Super Bowl Hangover."
Over the past decade, four of the 10 teams that lost the Super Bowl failed to make the playoffs the next season. Half of the six teams that did make it were one-and-done.
The last Super Bowl loser to make it back to the biggest game in football was the 1993 Buffalo Bills, who perfected the art of coming up short in that game.
Jim Harbaugh is as focused a head coach as there is, and the 49ers, barring a disaster, are an excellent bet for a playoff spot. However, the team can still send a message that the past is the past by coming out and dropping the hammer in this game.
Were this the regular season and were Adrian Peterson playing the whole game, it would take a remarkable effort from "All Day" for the Vikings to have a chance in this game.
It's just not a good matchup for the Vikings. The 49ers have one of the best front sevens in the NFL, and San Francisco will just load the box until Ponder shows some aptitude at making them pay for it.
Yes, the Vikings handled San Fran last year in Minnesota, but that was with Alex Smith under center for the Niners, and I'd wager that the 49ers haven't forgotten that game either.
The reserves may close the gap in the second half, but the battle of the first-stringers will be all San Francisco.
Final Score Prediction: San Francisco 23, Minnesota 13