The Falcons' victory celebration had to be tempered Monday, as the team learned CB Brian Williams would miss the rest of the season with a torn ACL, a source told FOXSports.com.

Williams had started all five games since signing with Atlanta just before the season. He was able to contribute right away due to his familiarity with the team's defense — a similar scheme to the one he played in when Falcons head coach Mike Smith was his defensive coordinator in Jacksonville. The eight-year veteran made 18 tackles and had one interception before getting hurt in the fourth quarter of Atlanta's 21-14 win over Chicago.

The Falcons have some options on who to move into the starting lineup. Nickelback Brent Grimes will probably not change roles, so Chevis Jackson and Tye Hil are the most likely replacements for Williams, although Jackson may have the early advantage since Hill is still trying to learn the defense after coming over in a preseason trade from the Rams.