Quarterback Gus Frerotte is doubtful for the game Sunday against Arizona with a lower back injury, meaning unless he’s a fast healer, backup Tarvaris Jackson will get the start

Coach Brad Childress said today that Frerotte is improving and will continue to be evaluated on Saturday and Sunday. But all signs point to Jackson being under center. He took all the snaps in practice this week and played very well in emergency duty last week against Detroit.

Right tackle Artis Hicks also is doubtful with an elbow injury. Defensive ends Jared Allen and Brian Robison are questionable with knee injuries. Kick returner Darius Reynaud is out with a bad foot.