The Buffalo Bills are bad. Some say very, very bad.

And on Sunday, as the team was once again getting blasted — the Bills were down by 28-6 at halftime — one of its most decorated players decided he no longer wanted to play.

In a puzzling and highly unusual move, cornerback Vontae Davis, a former first-round pick and two-time Pro Bowler, “pulled himself out of the game,” according to Coach Sean McDermott.

“He communicated to us that he was done,” McDermott said, adding that Davis, who had made one tackle, was not injured.

As it turned out, Davis did more than just skip out on the second half. He retired from the N.F.L. altogether.