EDEN PRAIRIE (AP) — The only certain thing about the availability of Vikings receiver and kick returner Percy Harvin for Sunday’s game at Chicago is that it’s uncertain.

Harvin is now listed as questionable for the game because of lingering migraine headaches.

Coach Brad Childress said the problem “hasn’t completely cleared” and initially described Harvin as “doubtful” to play the Bears, but the team decided on questionable — or 50-50 — when the official injury report was released Friday.

Harvin took part in drills Friday after absences the previous two days. He has played through the migraine condition several times before.

The availability of fellow wide receiver Sidney Rice for the Bears game is also unknown. Childress called Rice questionable, though he’s still on the physically unable to perform list and won’t appear on the official injury report.