After Nathan Peterman failed for the third straight time to finish a start, and was yanked midway through a game due to performance for the second time,  the Bills brass believed they had no choice but to demote the second-year quarterback and promote rookie quarterback Josh Allen this week, sources said.

While Peterman's sample size is on the small side -- again, just three starts over the past two seasons -- the extent of his problems against the Ravens in Week 1 led to a collective understanding within the team's coaching staff and front office that a change was necessary.

The Bills were hoping that Peterman could hold down the job for a while, allowing Allen, the first-round pick they moved up to draft in the top 10 in April, time to learn and adjust, and allowing the Bills to assess their revamped offensive line and skill players. They were comfortable with the idea that Peterman could start in the short-term and display an ability to run the offense, but after posting a 0.0 rating in Baltimore (with no first downs in the first half), and having thrown five interceptions in one half of football in his first start at the Chargers a year ago, sources said there wasn't much debate internally about turning to Allen.

"You wish you had more to go on than just the three starts, and it might be different if this was a veteran with a five-year body of work," said one team source. "But you don't have anything else to go on, and after it happens a second time you can't just write it off as an anomaly."

The initial quarterback competition was a close call between Allen and Peterman once AJ McCarron was dealt to the Raiders, and there was some back and forth within the staff about whether or not to start Allen right from the start of the season, given how close the battle was. Ultimately, with Peterman more consistent in the preseason games and practices -- and Allen flashing higher ability but suffering from more ups and downs -- the decision was made to open the season with Peterman.

Sources said the Bills are continuing to monitor the waiver wire and other team's depth charts, and could add another quarterback to the mix if it is the right fit.