Vikings first-round picks Kalil, Smith maturing quickly

A snapshot look at the Vikings as they prepare for Sunday's regular-season opener against the Jaguars at Mall of America Field.

Left tackle Matt Kalil and safety Harrison Smith. Yes, there likely will be a lot of attention paid Sunday to a certain eager running back wearing that No. 28 jersey and to Christian Ponder, the second-year quarterback whose 2012 development might be the biggest X-factor in the rebuilding efforts. But in Week 1, this year's two first-round draft picks will need to provide early evidence that they are as good as the Vikings believe them to be.

Both Kalil and Smith will start. And the Vikings hope they can permanently ink both players into those roles for years to come.

Kalil has shown noticeable growth since his arrival, particularly in jelling with left guard Charlie Johnson.

Said coach Leslie Frazier: "Once we got into padded practices, for them to be able to communicate and work off one another [helped Matt] being able to get more accustomed to our offense. ... But his confidence, his athletic ability, his knowledge, all of those things have been there."

Smith, meanwhile, was singled out this week by defensive coordinator Alan Williams as "a calming influence" for the defense. The coaches love his tenacity and reliability for almost always being where he's supposed to be. Now it's time for all that to show up on game day.

Will Adrian Peterson play? Yeah, yeah, yeah. We've asked that question 2,832 times since training camp opened in July. But Friday was the last opportunity to do so before the opener. And here's what Frazier had to say after Friday's practice: "There's no reason to make a decision before Sunday. We're going to talk with him again tomorrow and see how he feels and we'll make a decision."

Peterson is officially listed as questionable on the injury report.

The Vikings only have three backup offensive linemen on their 53-man roster. One (Geoff Schwartz) is just 33 days removed from sports hernia surgery and might not yet be back in game shape. Another (Mark Asper) arrived as a waiver wire pickup from Buffalo last weekend and will be inactive Sunday. So that might leave Joe Berger as the only dependable reserve for the opener. Berger filled in at both guard and center a year ago and did well when called upon. But what would happen if either starting tackle, Kalil or Phil Loadholt, were injured? Logic says Johnson would be the emergency tackle option with Berger then moving into the open guard slot.

The Vikings, obviously, hope they don't have to visit any such contingency plans.

New coach Mike Mularkey recognizes the struggles quarterback Blaine Gabbert had as a rookie in 2011, averaging just 154 passing yards in his 14 starts while completing 50.4 percent of his passes and taking 39 sacks. But Mularkey also points out that Gabbert was 22 years old when he made his debut with just three college seasons under his belt. Gabbert also came out of a shotgun spread offense at Missouri. "It's a little more of a challenge when you've got to put him under center," Mularkey said.

Also, like Christian Ponder, last summer's lockout deprived Gabbert of the offseason work that could have accelerated his growth.

The Jaguars believe Gabbert's command and pocket poise are elevated from a year ago but won't have definitive proof until Sunday.

The Vikings list only two starters: Peterson and defensive tackle Letroy Guion, who's listed as probable because of a knee injury. Punt returner Marcus Sherels also is probable (ankle). Linebacker Marvin Mitchell, receiver Jarius Wright and safety Andrew Sendejo are out because of sprained ankles.

Jacksonville starters listed are receiver Justin Blackmon (probable, ankle); cornerback Derek Cox (doubtful, hamstring); and linebacker Daryl Smith (out, groin).