Vikings defensive tackle Kevin Williams has now missed three days of practice this week, and if he isn't able to show he can handle some contact on Friday morning, he might not be able to play on Sunday against the Detroit Lions.
Williams, who hyperextended his right knee on a low block by San Francisco's Joe Looney on Aug. 25, hasn't practiced since then. His knee continues to improve, coach Leslie Frazier said, but it remains to be seen how hard the Vikings will push the 32-year-old tackle for a Week 1 game, especially when rookie Sharrif Floyd is expected to be ready for Sunday after coming back from minor knee surgery.
"You wouldn't have to see as much from Kevin as you would some other guys, because of his experience," Frazier said. "But still, there are certain things you want to make sure he's able to do to protect himself, and we'll see tomorrow if he's able to do some of those things."
In other Vikings injury news:
Floyd was officially limited on Thursday, but Frazier said there are no "ill effects" from his injury. "He's full-speed ahead," Frazier said.
Four of the other five Vikings players who were limited participants on Wednesday -- Phil Loadholt, Cordarrelle Patterson, Mistral Raymond and Letroy Guion -- were limited again on Thursday. Harrison Smith, who was limited on Wednesday with a back injury, returned to full participation on Thursday.