Both were listed as questionable -- Mankins with hip and calf injuries and Chung with a shoulder injury.
In addition to Mankins and Chung, the other inactive players are backup defensive end Jake Bequette, reserve defensive tackle Ron Brace, linebacker Tracy White (core special teams player), No. 2 running back Brandon Bolden and starting safety Steve Gregory.
Mankins projects to be replaced by fifth-year veteran Donald Thomas, who had filled in for Mankins in a 52-28 win over the Bills on Sept. 30.
With both starting safeties out, the Patriots could be forced to play with rookies Tavon Wilson (second round) and Nate Ebner (sixth round), the combination that was on the field for the Seahawks' game-winning 46-yard touchdown pass last week.
However, there are other options, such as Sterling Moore, who has played safety in the past. Cornerback Devin McCourty also has experience at safety, but if the team moves him there, it would have to shuffle some parts at cornerback.