Nall, who has gotten off to slow starts in each of his previous three training camps in Green Bay, struggled in a scrimmage Thursday evening against the Bills. On one series, he threw an interception and was sacked on the next play.
O'Sullivan has been steady but hasn't completed deep passes on a consistent basis, or difficult throws over the middle. He has been very cautious with his passes, often tossing short passes to running backs in the flat.
Either Nall or O'Sullivan will have to begin making some plays in Friday night's scrimmage in Lambeau Field against the Buffalo Bills and in the Packers' first preseason game against San Diego on Aug. 11. If not, one will will be out the door by the end of August and the other will be third string behind Rodgers and Favre. There also is a possibility that both could be released and the Packers sign a different veteran QB.