Vikings middle linebacker E.J. Henderson was listed as questionable for Sunday's game against the San Francisco 49ers after today's practice.

Henderson was held out of practice Wednesday and did limited work Thursday after bruising his shoulder last Sunday against the Lions. Henderson said he suffered the injury in the fourth quarter when tackling Lions tight end Brandon Pettigrew in the open field.

Henderson suffered a season-ending injury to his foot in the fourth game of last season. Asked how tough it would be to miss this game, Henderson said: "It would be frustrating but it's a long season. I'd rather be there for the end then the beginning."

If Henderson is unable to play it's expected that rookie Jasper Brinkley would get the start at middle linebacker. Brinkley said Thursday that he has grown comfortable in the Vikings system.

As for wide receiver Percy Harvin, he was at Winter Park today but did not take part in practice for a second consecutive day because of an illness. He was listed as questionable for Sunday's game.

Coach Brad Childress said Harvin is still ill but expressed confidence that the rookie could play if he's OK. "I think we could get him up to speed," Childress said. "Just see how he's feeling. That's what more than drives anything."

With the flu spreading around, and concerns about the H1N1 virus, Childress said the team is doing everything the team doctors have told them to do to limit the spread of germs. "[We're] washing our hands religiously," he said.

Meanwhile, running back Adrian Peterson, who was limited on Wednesday and Thursday, took part in all of Friday's practice and is probable for the game.

As for the presence of kicker Taylor Mehlhaff, the decision to have him at practice on Friday was very similar to what the Vikings did a few weeks ago when they brought in left-footed punter Glenn Pakulak before they faced Dave Zastudil in Week 1 at Cleveland. The 49ers' Joe Nedney is a left-footed kicker and Mehlhaff also kicks off with his left foot. Mehlhaff's appeareance at practice enabled the Vikings to get some looks, something that doesn't only benefit the return men but also can help the up men prepare if there is an onside kick.

UPDATE: Just got word from the NFL that defensive end Jayme Mitchell was fined $5,000 for unnecessary roughness for grabbing Kevin Smith's helmet opening on a tackle last week.

UPDATE: Here is the Vikings' injury report for today:

LB Erin Henderson -- calf -- did not practice Friday -- out for Sunday's game

LB E.J. Henderson -- shoulder -- limited participation Friday -- questionable for Sunday's game

S Madieu Williams -- shoulder -- full participation Friday -- probable for Sunday's game

RB Adrian Peterson -- back -- full participation Friday -- probable for Sunday's game

TE Jim Kleinsasser -- hand -- full participation Friday -- probable for Sunday's game

WR Percy Harvin -- illness -- did not practice Friday -- questionable for Sunday's game