On Sunday night, the Cardinals placed cornerback Robert Alford on injured reserve to make room for the arrival of Cassius Marsh. Alford suffered a tibia fracture earlier this month, which calls for at least another six weeks in recovery. By placing him on IR, the Cardinals have made him ineligible for at least eight games. 
The Alford injury hurts Arizona, especially since star cornerback Patrick Peterson is serving a six-game suspension for a PED violation. The Cardinals will do their best to get by against the Lions, Ravens, Panthers, Seahawks, Bengals, and Falcons without P2, and the Giants and Saints (and perhaps others) without Alford.
If all goes well in Alford’s recovery, he could conceivably return for Arizona’s Oct. 31 game against the Niners. For now, the Cardinals will rely on Tramaine Brock and rookie Byron Murphy to start the season.