Mike Zimmer: 'Adrian Peterson was not tentative on return to field'

Minnesota Vikings head coach Mike Zimmer has insisted that Adrian Peterson was not tentative in his return to action against the San Francisco 49ers.

The 30-year-old rushed for 31 yards on 10 carries and had three receptions for 21 yards in his side's 20-3 defeat at Levi's Stadium in his first game since the opening weekend of the 2014 season.

"I don't think he looked tentative," Zimmer told reporters. "I think he was aggressive trying to get to the hole and maybe trying to get to it a little bit too fast at times."

Peterson missed the majority of the 2014 season after he was suspended from action by the NFL.