The Vikings have 11 offensive starters. At best, Shaun Hill and/or Sam Bradford rank seventh in order of importance as the Vikings head into Sunday's season opener at Tennessee.

No. 1 would be a fella named Adrian Peterson. Remember him? Five-time All-Pro and three-time rushing champ on a run-oriented team whose identity starts with defense?

Nos. 2-6 would be, in no particular order, left tackle Matt Kalil, left guard Alex Boone, center Joe Berger, right guard Brandon Fusco and right tackle Andre Smith.

"I think all the pressure is on us," Boone said Monday. "We have total faith in Shaun. But given the circumstances, we know the pressure comes down on the line. So we have to kick [Tennessee's] butt in the run game and let Adrian do his thing."

Boone said "Shaun" even though no one has or will name Hill the starter for obvious competitive reasons. Reporters aren't allowed to watch practice. But you do the math.

The Vikings' tentative plan heading into the week was to start Hill. This shouldn't surprise anyone because, well, it's never a real good idea to start teaching a game plan to a quarterback who's only had hours to learn the offense.

But even if Bradford channels his inner Einstein and aces the offense faster than Rain Man counting spilled toothpicks, the Vikings' success, especially early on this season, will depend on the offensive line and Peterson controlling the game.

Coach Mike Zimmer's toes hadn't thawed from the Seattle playoff loss by the time he declared the offensive line as the No. 1 offseason rebuilding project. Boone was the team's prized free-agent signing, and Tony Sparano was hired to teach, preach and pound mental and physical toughness into a unit that Zimmer felt coasted under former line coach Jeff Davidson.

The Battle Royale of competition up front never materialized because of Phil Loadholt's retirement and Mike Harris' mysterious ailment. John Sullivan gave Berger somewhat of a battle, but ultimately was no match for the bigger, stronger Berger.

Kalil improved because of Sparano's tips and defensive end Everson Griffen's speed, power and relentless work ethic. He also appears ready to return after missing a couple of weeks because of an injury.

Boone, meanwhile, has lived up to the hype. Fusco looks more comfortable back on the right side. Smith is still a concern against speed rushers, but should be an upgrade from T.J. Clemmings as an overwhelmed rookie a year ago.

"I think [the line is] much improved," Zimmer said. "You know Matt has been missing for a couple of days, but I think he's had a very good camp. I think Boone has added a lot. Fusco has looked much improved. Andre Smith has done a nice job in there and Berger as well. You always want it to be better. It wouldn't matter if they were five All-Pros, but I think they're much improved."

Tennessee presents more of a challenge than its 3-13 record last season would indicate. Now in his 58th NFL season as a player or coach, Dick LeBeau, the 78-year-old Hall of Famer, takes over the Titans' defensive play-calling duties a year after he assisted Ray Horton, who is now in Cleveland.

With LeBeau joining the staff a year ago, Tennessee went from 27th to 12th in total defense and 31st to 18th in run defense. That allowed new General Manager Jon Robinson, 40, to focus on the offense, where he beefed up the line and brought in running back DeMarco Murray, the 2014 league rushing champion.

Jurrell Casey, a Pro Bowler a year ago, had 11 tackles for loss as an end in Tennessee's 3-4 scheme. Meanwhile, the run blitzes LeBeau is known for helped Tennessee rank seventh in average yards allowed per carry (3.89).

"They're physical up front," Zimmer said. "I assume they'll be stacking the line of scrimmage with a lot of run blitzes, which they always do."

Even if they do, Boone sounds like a guy who can't wait to see what Peterson can do after being rested for the entire preseason.

"I think Adrian is ready to roll," Boone said. "And I've seen enough of Adrian to know we should be excited if he's excited."

Yes, it is a quarterback's league. But in the Vikings' current situation offensively, if Nos. 1-6 don't perform, it doesn't matter who No. 7 is or what he does.

Mark Craig covers the Vikings and the NFL for the Star Tribune. mcraig@startribune.com