Jerick McKinnon entered December with not only a spot near the front of the NFL’s rookie rushing ranks, but also a painful lower back injury.

Unexpectedly thrust into a starting role with Adrian Peterson banished from the Vikings, McKinnon surprised with 538 rushing yards through 11 games, two of which he played with the nagging injury. But in early December, the Vikings decided to shut him down for the rest of the 2014 season.

“It got to the point where it was just too bad, I guess,” McKinnon said.

In the season’s final month, McKinnon watched Cincinnati’s Jeremy Hill speed away to double him up in rushing yards, and a few other rookie runners passed by McKinnon, as well. McKinnon, who occasionally checked in on his peers more due to boredom than curiosity, finished eighth among rookies.

Looking back, he admits that the injury, which required surgery, was “really devastating” at first. He had performed well enough to climb the depth chart, then suddenly found himself standing on the sideline down the stretch instead of in the backfield next to rookie quarterback Teddy Bridgewater.

Now, as he is close to completing his post-surgery rehab program, McKinnon looks back on his rookie season much more favorably.

Jerick McKinnon averaged 4.8 yards a carry in 2014, third among rookie running backs.

“I was happy with how the season went. It was a blessing, just being able to play in the NFL, a dream come true,” he said. “I took it for what it was. I’m happy but I’m not content.”

While many of his teammates headed home after the season or to exotic locales much warmer than Minnesota, the Georgia native has stayed in the Twin Cities so he can rehab his injury at Winter Park with the team’s athletic training staff. He has only a couple more weeks left before the process is completed.

“It’s been pretty good. It’s been a long process, but that’s just the way it goes after surgery. I’ve been here all offseason working really hard,” McKinnon said last week in a phone interview. “I’ve just been in the training room with [assistant athletic trainer] Tom Hunkele pushing myself to the limit and just trying to get back ready. It’s been a long grind but it’s definitely working.”

There have been no setbacks, and McKinnon says he will be ready to participate without any limitations in the offseason workout program, which can begin April 20.

Of course, it’s unknown who will be joining McKinnon at the facility this spring. Will Peterson be reinstated and still be a member of the Vikings? Will restricted free agent Matt Asiata return? Will the Vikings add a free-agent back? Will they select another young runner in the NFL draft, which begins April 30?

“You’ve got to just do what you do and not worry about stuff you can’t control,” McKinnon said of all the uncertainty as his position.

Instead, McKinnon is focused on building on his solid rookie season.

Only three rookie running backs averaged more yards per carry than McKinnon, who averaged 4.8. Only two, Hill and St. Louis’ Tre Mason, averaged more rushing yards per game. And his four runs of 20-plus yards were fourth among rookie backs.

McKinnon plans on improving his overall game, but will place an extra emphasis on getting stronger so he can survive a full season of pounding between the tackles, and also pass protection, an area of his game that was subpar in 2014.

That way if he is called on to start again, he will be even more ready.

“I’m expecting bigger and better things for myself,” McKinnon said.