Vikings coach Mike Zimmer got word less than three hours before Sunday's game that defensive end Everson Griffen was sick and wouldn't play. That didn't give rookie backup Danielle Hunter much time to prepare, but he looked more than comfortable filling in at the last second.

Hunter had four tackles, half a sack and was credited with a forced fumble in the Vikings' 16-10 victory over Kansas City at TCF Bank Stadium.

"It was pregame," Hunter said about when he got word that he'd start. "We practiced all week and we always have to be ready for the game. Coach preaches to us about always being ready to be the next man up."

Hunter combined with tackle Sharrif Floyd to sack Alex Smith on third down deep in Chiefs territory during their first drive of the second quarter, jump-starting a Vikings scoring drive.

The forced fumble credited to Hunter ended the Chiefs' second-to-last drive of the game. Replays showed that Chiefs offensive lineman Donald Stephenson accidentally knocked the ball out of Charcandrick West's hands, but Hunter was already engaged with West when the ball came loose.

"[I] saw the ball, so I reached for the ball and tried to make the tackle at the same time," Hunter said. "It was exciting. They were driving down the field and we had to make a play to stop them."

Pro Football Talk reported that the NFL will investigate the Vikings' failure to disclose Griffen's illness before making him inactive on Sunday, saying the league requires teams to report any player who has an injury or illness that could impact his ability to play to the media and the opposing team's staff.

Zimmer wouldn't elaborate on Griffen's illness, only that he expects Griffen to return to practice this week.

Rookie show

Hunter wasn't the only rookie to stand out Sunday.

Fifth-round pick Stefon Diggs led the team with seven catches for 129 yards.

Second-round pick Eric Kendricks had 10 tackles and a sack in his first game managing a full-time role at linebacker. He assumed the bigger role when the Vikings traded linebacker Gerald Hodges to San Francisco during the bye week.

First-round pick Trae Waynes rotated in at cornerback and recorded three tackles. Fourth-round offensive lineman T.J. Clemmings limited the impact of the Chiefs' edge rushers, including Pro Bowl linebacker Justin Houston.

"We just work hard," Kendricks said about the rookies. "We obviously have talent, that's why they drafted us. All we got to do is meet expectations and come out and work, then our work will showcase on the field.

"It's cool [to see us make an impact.] The defense is starting to click for us. As rookies it takes a while, but I think things are starting to fall in."

Walsh rebounds

Blair Walsh was 3-for-3 on field goals, converting from 24 yards and twice from 45.

"It's nice to be consistent in that game," Walsh said. "It's nice that I can take those three kicks and build on them. I did some things that I've been working on the last two weeks.

"We needed it. It was one of the games where the other team kept hanging around and we didn't really put them away how we wanted to, and our special teams had to step up and we did."

Peterson struggles

Adrian Peterson struggled to collect 60 yards on 26 carries and was banged up along the way. He said he jammed a finger on his left hand early in the game, but "it'll be good."

The trainers were wrapping the fingers on Peterson's left hand late in the game, and he sat out the Vikings' final drive. Zimmer also said it was nothing serious.

"We knew that coming into the game, we were playing with a physical group," Peterson said. "Those 1-, 2- and 3-yard gains helped us keep some drives alive."

Etc.

• Penalties plagued the Chiefs. They had eight for 95 yards and several times negated good gains with the mental miscues. "Fifty-one yards of total offense in the first half and 50 yards of penalties is completely unacceptable," Chiefs coach Andy Reid said.

• Kyle Rudolph scored the Vikings' only touchdown with 4:43 left in the second quarter. With Peterson unable to find holes, Teddy Bridgewater went to the big tight end over the middle and found him in the back of the end zone.

• Tight end Rhett Ellison helped set up the touchdown with an 11-yard reception three plays earlier. He caught the short pass and charged into two defenders before being stopped at the 3-yard line.

• Defensive tackle Shamar Stephen left the field on a cart in the third quarter and didn't return. It was announced as a toe injury and Stephen was wearing a boot on his left foot after the game.