Reed was listed on Friday's injury report as "doubtful" with groin and foot ailments. He sat out the Ravens' 27-14 loss to the Green Bay Packers on Monday night with what was described as a hip injury. Reserve safety Tom Zbikowski will likely start against Detroit.
In other Ravens injury news, starting receiver Mark Clayton is also doubtful with a knee injury, and linebacker/defensive end Terrell Suggs (knee) is questionable. Suggs missed the past three games for Baltimore but will be a game-time decision on Sunday.
James Walker covers the AFC North for ESPN.com.