Even now Jerome Felton is helping. Lead blocking, if you will, when it comes to helping his teammates prepare to replace him. He has become an important resource on all things fullback.

"We'll do it all this week," Rhett Ellison said. "[Sunday], we were working on Detroit. His insight is huge."

All during preseason, complaints about the Vikings offense were offered with the caveat that we hadn't seen that offense with all-world running back Adrian Peterson. Well, Peterson is back, this week, full-force, as the Vikings prepare for the season opener in Detroit.

But, now, here's the question: How will Peterson run — and the Vikings offense fare — without Felton leading the way for him?

Felton was the man who helped Peterson embrace the idea of even having a lead blocker in the first place. Last season, as Peterson was chasing 2,000 yards, it was Felton leading the way at fullback, eventually earning Pro Bowl honors and a new contract from the Vikings. But now, with Felton about to start serving a three-game suspension, it remains to be seen how much the Vikings offense will change while he's gone.

Will the Vikings use Peterson more without a lead back? Or will they just plug in someone else in?

And, if so, who will that be?

It could be Ellison, the combination tight end/running back who was drafted in the fourth round in 2012. Or rookie Zach Line, who bucked the odds by making the 53-man roster while transitioning from college running back to pro lead blocker.

"We're counting on Zach and Rhett to really help us in that area,'' Vikings coach Leslie Frazier said. "Along with [tight end] John Carlson. We're still going to be in some two-back situations when we line up on Sunday. And we think those guys can be capable of getting the job done."

According to ESPN Stats & Information, Peterson's success last season with a blocker far outstripped his performance without one. He averaged 7.25 yards per rush with a lead blocker, scoring eight of his 12 touchdowns. Without a lead blocker, he averaged 3.8 yards per carry.

Now we'll find out how successful Peterson can be without Felton, who was suspended by the NFL because of a drunken-driving arrest in 2012. Felton pleaded guilty to a lesser charge of careless driving, but the suspension was issued because it was his second drunken driving charge.

Ellison figures to get the most work in Felton's absence. His style is reminiscent of former Vikings tight end — and run-blocking legend — Jim Kleinsasser. Ellison, who wears Kleinsasser's No. 40, needs to show he can do the lead blocking job out of the backfield.

"He's one of the hardest workers on our team," Frazier said. "It's hard to outwork Rhett. He comes prepared every single day."

Ellison and Line both have been working hard with Felton — who still is allowed to take part in team and position meetings — as the regular season approaches. They have peppered him with questions, watched his film.

For Ellison, lead blocking is pretty much the same no matter for whom he's doing it. Almost.

"Whether it's AP or Toby [Gerhart], you're protecting your brother in the backfield. But, with Adrian, you have to move faster. You have to do the job, then get out of his way."

Line, meanwhile, is trying to learn a new position after being the primary ball-carrier in a spread offense at SMU.

"The hardest thing for me is, I've always been able to decide where to go," he said. "Now, as a lead blocker, you have to block for someone else. You have to take guys on squarely, and let [the ball-carrier] decide where to go.''

He's still working at it. That and working on his leverage as a blocker. He ran high as a running back but has to stay low as a fullback.

Most of all, Line — and Ellison — have been poring over film of last season, watching what Felton did.

Ultimately it will take a number of players to keep Peterson moving. A fullback at times, a tight end, either on the edge or in motion. We'll find out Sunday how much missing Felton will affect the Vikings.