Ability has never been an issue for Vikings defensive tackle Sharrif Floyd. As for durability, well …

On the heels of last Sunday's standout game, the former first-round draft pick missed his third straight day of practice Friday and was ruled out of Sunday's game at Detroit because of knee and ankle injuries. Backup Tom Johnson, the team's inside pass rusher in the nickel package, will start.

"I think Tom's played good all year, really," Vikings coach Mike Zimmer said. "He did a great job in the preseason and has done a good job all year. I think we should be fine."

Johnson, who had a career-high 6½ sacks a year ago, has played 187 of the 348 defensive snaps (53.7 percent) this season and has one sack and two tackles for loss. Floyd has started the first five games and has played 226 snaps (64.9 percent).

In his first two seasons, Floyd's play was affected for long stretches by nagging injuries. He missed two games and five starts a year ago but appeared to be healthy for the first five games of this season.

In last week's 16-10 win over the Chiefs, Floyd was a consistent force and also made two of the bigger plays in the game. He notched half a sack and also broke through the offensive line to make the tackle for no gain on fourth-and-1 at the Vikings 7-yard line.

There was no mention of the injury Sunday.

Trattou out again

Defensive end Justin Trattou, who hasn't played since Week 3 because of a foot injury, was listed as out.

The other players on the injury report had full participation in practice and were listed as probable for Sunday. They are: defensive end Everson Griffen (illness), running back Adrian Peterson (finger), cornerback Terence Newman (ankle), offensive tackle T.J. Clemmings (knee), running back Matt Asiata (rib), receiver Charles Johnson (rib), receiver Jarius Wright (hand) and cornerback Captain Munnerlyn (thumb).

With Trattou and Floyd out, defensive lineman Kenrick Ellis, a five-year veteran nose tackle, is expected to be active and possibly play. Ellis, who was with the Giants earlier this season, was signed Tuesday when defensive tackle Shamar Stephen was placed on injured reserve.

"I think [Ellis has] got a chance to be a pretty good nose tackle," Zimmer said. "He's strong. Got good quickness. Massive [6-5, 335]. And he moves good."

Diggs with No. 1 unit

For what it's worth, rookie receiver Stefon Diggs was working with the first team during the brief open portion of practice. That's an indication but not a guarantee that he'll start ahead of Johnson on Sunday. Johnson has missed the past two games because of a rib injury but is expected to be healthy enough to play Sunday.

After Friday's stretching and individual drills, the quarterbacks and receivers went to work on some goal-line routes. Diggs was working with the No. 1 three-receiver set along with Mike Wallace and Jarius Wright.

Asked whether he's decided on a starter there, Zimmer said, "I've got an idea. But there's no sense in telling everybody."

Calming Diggsmania

Offensive coordinator Norv Turner is a fan of Diggs. He made a point to mention that Thursday when he said, "Diggs has been impressive since he got here."

However, the old-school coach in Turner is chafing a bit over the media and fan sensation that Diggs has become after only two games in which he has caught 13 passes for 216 yards. The hoopla continued Friday when Diggs was named the Pepsi NFL Rookie of the Week in a vote by the fans.

"I'm going to slow that down," Turner said. "He's got a lot of work to do. We went in [Sunday] and played a man [coverage] team [Kansas City] and put in a couple of routes that they've never seen us run and he did a great job running them. He caught I think four balls in the first quarter.

In other words, easy does it, folks.

"He's going to be a really good player, he just has a lot of work to do," Turner said. "The good thing about him, he understands that and that's the way he approaches it. He comes in here every day with a mind-set that he's going to get better."