EDEN PRAIRIE, Minn. -- The only certainty in Minnesota's wide receiver group this season has been, well, uncertainty.
Percy Harvin returned to practice Friday after absences the previous two days, but Vikings coach Brad Childress said his migraine headaches haven't "completely cleared."
Childress even initially described Harvin as "doubtful" to play Sunday at Chicago, before deciding on questionable -- or 50-50 -- for the official injury report when it was released about an hour later.
Harvin also has been dealing with a sprained ankle, but Childress said that hasn't been a problem for him this week.
As for Sidney Rice?
"The decision is up to Sidney when he's going to jump back in," Childress said.
Also, the next-most important player at the position, Bernard Berrian, now has a groin injury. He was limited in practice Friday and is listed as questionable.
Rice remains on the physically unable to perform list -- the Vikings must decide by Saturday afternoon whether to activate him for the Bears game -- so he does not appear on the injury report. But Childress assessed him as questionable.
Rice said he wanted to see how his body feels Saturday before making a decision on whether he feels confident to complete his comeback from the hip surgery he had in late August. He practiced hard Thursday and reported some soreness Friday, but both Childress and Rice said he hasn't had any setbacks.
"Don't have that explosion that I used to have at this point, but it's getting better. It's coming back," Rice said.
Asked how important his long-term health is in his decision to take the field again, Rice said, "It's huge. Definitely, I want no setbacks, but I also want to help this team as much as I can."
On the defensive side, cornerback Asher Allen (concussion) and safety Jamarca Sanford (hamstring) have been listed as doubtful. Rookie Chris Cook is expected to return to the starting lineup in Allen's place.
"It's been looking that way all week," Cook said.
It's been looking all fall like this will be Brett Favre's final season, although he's famously changed his mind before. In an interview with the NFL Network this week, Favre hesitated and then answered "no" when asked the burning question about whether he'll play in 2011.
Childress said he hasn't broached the subject with Favre.
"I think he's got his head pretty well set on it," the coach said. "That's what he's saying and he's said from the very start."
The 41-year-old is also the subject of a league investigation into alleged advances made with graphic photos, text messages and voicemails to a former New York Jets employee when he played for the team in 2008.
The woman, Jenn Sterger, met with league officials about the matter Thursday and provided them with "substantial materials," according to her manager, Phil Reese. NFL spokesman Greg Aiello said there would be no announcement Friday.