Saturday night’s heavy rains in Nashville won’t make it easy for the Green Bay Packers to evaluate roster competitions at certain positions.  At quarterback, where Matt Flynn and Scott Tolzien are competing for the Number-two job, both had to deal with fumbled snaps and receivers who had trouble running routes and catching passes.  Flynn started and led the Packers on a single scoring drive, completing five-of-ten passes for 49 yards, for a 64-point-two passer rating.  The weather was better for Tolzien — and when it didn’t rain, he made hay as completed 8-of-12 for 124 yards, and a 100-point-seven rating. The entire Packer roster will have a better chance to show their stuff this Saturday afternoon under the dome at Saint Louis.  The Packers will have a closed practice today.