FLOWERY BRANCH, Ga. (AP) - Atlanta Falcons offensive lineman Joe Hawley has been suspended four games for violating NFL rules against performance-enhancing substances.

The league announced the penalty Monday, one day after the NFC-leading Falcons improved to 9-1 with a 23-19 victory over Arizona.

Hawley is a backup behind Falcons longtime center Todd McClure. The suspension begins immediately, meaning Hawley can't return to the Atlanta roster until Dec. 17 - a day after the team faces the defending Super Bowl champion New York Giants.

While Hawley is out, the Falcons will likely use rookie Peter Konz as McClure's backup. Konz is also the starter at right guard.