The Lions' secondary is banged-up, with cornerback Chris Houston (toe) and backup cornerback Darius Slay (knee) not practicing all week and listed as doubtful. Slay had arthroscopic knee surgery last week. The Lions have just four healthy cornerbacks: Rashean Mathis, Bill Bentley, Jonte Green and Chris Greenwood. If Houston doesn't play, Mathis and Green would start with Bentley operating as the nickel. … Running back Reggie Bush (calf) practiced for the second day in a row and is questionable, along with defensive end Ezekiel Ansah (shoulder). Five players are probable for Detroit: Johnson (knee), safety Louis Delmas (knee), defensive end Israel Idonije (knee), offensive tackle LaAdrian Waddle (elbow) and safety John Wendling (illness).