The best graybeard among NFL running backs will play Sunday at U.S. Bank Stadium.

No, not Adrian Peterson, who returns from injured reserve to join the Vikings’ playoff push.

Adrian is a pup compared to this other guy. In fact, this other guy is someone the 31-year-old Peterson once looked up to while in college.

Colts running back Frank Gore, 33, will play in his 94th consecutive regular-season game and make his 90th straight start, both of which lead all NFL backs. He hasn’t missed a game since the start of the 2011 season and ranks eighth on the NFL’s career rushing list with 12,830 yards.

And, oh yeah, this is a guy who tore his left ACL in 2002 while still at the University of Miami. Peterson tore his in 2011 and used Gore’s story as part of his motivation en route to 2,097 yards and league MVP in 2012.

“He’s been in the league 12 years — two years ahead of me — and he’s been playing at such a consistent level, racking up [eight] 1,000-yard seasons,” Peterson said. “I’m sure he does a lot of praying and I know mentally his mind is in a great place. To be able to play as long as he has played and to be able to overcome the injuries that he has, mentally, you have to be on a totally different level.”

Gore ranked 15th on the career rushing list when the season began. He was 365 yards ahead of Peterson, who was 17th.

The assumption was Peterson would race up the career list, passing Hall of Famers while catching up to and surpassing Gore as well. After all, Peterson had just become only the third player in his 30s to lead the league in rushing. He ground out 1,485 yards behind a struggling line while Gore had gained 967 as more of a secondary weapon in his first year with the Colts after a decade with the 49ers.

Peterson tore the meniscus in his right knee in Week 2 and hasn’t played since. He’s at 50 yards on 31 carries (1.9). Meanwhile, Gore is 14th in the league with 790 yards on 208 carries (3.8).

Peterson did pass Fred Taylor to rank 16th in career rushing. But Gore has passed six Hall of Famers — Thurman Thomas, Franco Harris, Marcus Allen, Marshall Faulk, Jim Brown and Tony Dorsett — and Edgerrin James, who was a Hall of Fame finalist last year and probably will be again this year.

Gore isn’t going to take over Sunday’s game. The Colts don’t use him that way. But he still runs with unusual quickness and power for a 33-year-old guy who stands 5-9 and weighs 217. And he’s an excellent receiver, having joined Walter Payton, Curtis Martin, Emmitt Smith and LaDainian Tomlinson as the only players in NFL history with at least 12,500 rushing yards and 400 catches.

“I don’t see a 33-year-old, I see a great back,” said middle linebacker Eric Kendricks, a key defender in stopping Gore, making the Colts offense one-dimensional and unleashing the Vikings’ pass rush.

“Being a California kid, I see one of my favorite backs ever from when I was growing up. I think it’s really awesome that I get to play against him. It’s so cool.”

Vikings cornerback Captain Munnerlyn sees something else.

“That guy put stitches under my chin, man,” Munnerlyn said. “I was with Carolina and we played against the 49ers. I came in on a blitz and he unloaded on me. I was like, ‘Wow.’ He’s definitely a tough running back. He’s one of the best in the business.”

That Peterson fella isn’t bad either.

A reporter asked him this week if he could pinpoint what has been missing in the Vikings’ 32nd-ranked running attack this season.

Perhaps hesitant to toot his own horn too loudly, Peterson said: “What do you think? I’ll get your opinion first. What do you think has been missing?”

Another reporter chimed in and said, “No. 28.”

“That’s a great point,” said Peterson, No. 28 and the young buck among the top-20 career rushers who will play at U.S. Bank Stadium on Sunday.