Five games into the post-Michael Vick era, the Atlanta Falcons already have a quarterback controversy and plenty of grumbling players. Rookie coach Bobby Petrino insisted Monday that Joey Harrington is still the No. 1 quarterback, but former Jacksonville starter Byron Leftwich is waiting in the wings for his chance to lead the struggling team. Harrington was yanked early in the fourth quarter of Sunday's loss at Tennessee after completing 16 of 31 passes for 87 yards. Leftwich was even worse, completing just 2 of 8 for 28 yards and tossing a crucial interception with less than 3? minutes to go. "Our best chance of success is to stay with Joey," Petrino said, having reviewed film of the miserable offensive performance. "I think he understands our offense. He knows what we want to do and how we want to execute."