Billings notched two tackles in the Bears' 17-9 loss to the Packers on Sunday.
The Bears signed Billings to a two-year, $8.5 million contract extension Thursday, Adam Schefter of ESPN reports.
Billings signed a contract with the Bears on Thursday, Dan Wiederer of the Chicago Tribune reports.
Billings (lower leg) is listed as active Saturday at Pittsburgh.
Billings (lower leg) is listed as questionable for Saturday's game against the Steelers.
Billings (lower leg) has been ruled inactive ahead of Sunday's game versus New England.
Billings (lower leg) is listed as questionable for Sunday's contest against the Patriots, Vic Tafur of The Athletic reports.
Billings (lower leg) has been ruled out for Thursday's game against the Rams, Vincent Bonsignore of the Las Vegas Review-Journal reports.
Billings suffered a lower-leg injury during Sunday's overtime win in Seattle.
Billings (undisclosed) was not listed on the Raiders' injury report Wednesday, Rachel Gossen of the team's official site reports.