Rookie running back Jerick McKinnon had a break-out game yesterday, showing off his wheels while rushing for 135 yards in a 41-28 win over the Falcons. But today, head coach Mike Zimmer pumped the breaks a little bit on the notion that McKinnon is ready to be an every-down back.

Zimmer said that as a defensive-minded coach, he likes the challenge that a committee approach can pose to defenses. Besides, there are only a handful of true all-situation backs in today's NFL.

Starter Matt Asiata is more of a physical, between-the-tackles runner. Meanwhile, McKinnon, a third-round pick in May's NFL draft, has the quickness needed to get around the edge and the speed and shiftiness to be a big-play threat when he gets into the open field. But while McKinnon has some pass-catching skills, he is not polished when it comes to things like pass protection.

"I think he's a change-of-pace back for us," Zimmer said. "We'll worry about next year [then]. I hope we can continue to grow his role but I don't think he's going to be an every-down player right now."

Asiata got the first six carries of the game yesterday and scored goal-line touchdowns on two of them. McKinnon got his first carry on the team's third offensive drive and took off for 55 yards.

On 18 carries, McKinnon nearly doubled the rushing production of Asiata, who had 78 yards on 20 carries. But Asiata got the call at the goal line, and rewarded the Vikings with three touchdowns.

Zimmer said the offensive play calls won't necessarily change when they switch running backs. But he suggested that Asiata and McKinnon might read the plays and run the ball different ways.

McKinnon is comfortable sharing the backfield with Asiata, but he does have greater aspirations for the future, which may or may not include Adrian Peterson, whose status here is up in the air.

"I've been improving in pass protection and other things besides running the ball," he said. "I think I can develop into an all-down running back. That's something that I have my eyes set on."