EDEN PRAIRIE, Minn. — Ronnie Hillman is ready for the learning curve.

The Vikings announced Wednesday they added the 2012 third-round pick to the roster after an injury to Adrian Peterson.

Hillman said his biggest challenge will be picking up Minnesota's offense.

"Hearing the new plays kind of makes your head spin a little bit," Hillman said. "It takes time, but I'll get it.

"You hear plays that are similar to the ones that you (know)," he added. "It should be a quick turnaround, and I'm ready to get going."

Added Vikings Head Coach Mike Zimmer: "It's his first day here, so he's got a lot to learn."

The 25-year-old running back spent the past four seasons in Denver. He has 1,842 career rushing yards and 12 career rushing touchdowns.

Hillman faced the Vikings last season as he had 11 carries for 103 yards, including a 72-yard touchdown run.

Hillman, who said he brings a speed element to the field, added he's excited to be in Minnesota.

"They've got a lot of young talent here," Hillman said. "Even with the injuries, they still have a lot of young talent.

"They're a tough team, I played these guys last year," he added. "Their defense is great."

Hillman was released by the Broncos earlier this month after helping Denver defeat Carolina in Super Bowl 50 in February.

Zimmer said the Vikings are likely to start Jerick McKinnon this week at Carolina, and Matt Asiata is also expected to contribute.